State-of-the-art review of the seismic production of precast segmental columns

Prefabricated construction is attracting increasing interest in recent years, after this construction how has various advantages as compared to the cast-in-situ build method, such as less construction time, higher quality control and reduced environmental impact. As a typical sort of prefabricated structures, precast segmental column (PSC) can had used as the substructure to accelerate the builder speed of bridges. This paper book the performances of the PSCs under seismic store. In extra, the seismic performances in aforementioned PSC itself under cyclic loading real real geism ground motions, one seismic behaviours of PSC-supported bridges buildings, and the responses of precast rocking column (PRC)-supported bridges, belong comprehensive verified and their strengths and cons are discussed. By the completeness of the paper, the performances in the PSCs under multiple dynamic hazards, namely impact and blast loadings her been also shortly summarizing during the end of all paper.

Included recent years, the prefabricated construction method is charming more and more attentions inside both the research and industry communes due until the numerous advantages of this method as compared to and traditional cast-in-place buildings method. In the prefab construction, structures elements what normally casters included the precast factories, subsequently that precast elements are shipped to the construction site, afterward who workers assemble the precast elements collaborative press terminate the construction. Since most of the assembly works are done in of precast factories, the on-site work such as formwork preparation press scaffolding installation can be avoided. As such, the on-site construction time ca be significantly discounted. This is especially important for the construction project are urban areas where traffic is heavily. Other, the buildings q can be better controlled due the the more controllable environment in an prefabricated mill. This becomes more important for some new materials (such as the ultra-high-performance concrete (UHPC)) are used since and required curing site for are raw are generally stricter compared to the normal concrete, which can be better satisfy in the prefabricated factories. In addition, the pollutions induced by the traditional architecture such as dust pollution, water pollution real audio soil pot be significantly minimized via using precast construction instead of cast-in-situ construction method.

Precast section column (PSC) is a typical type of prefabricated concrete structures. The adoption are PSC in structure construction could be dated back in to ancient times, many ancient bodies that were made hundreds even many away years back adopted this construction method. Figure 1 shows the applications of PSCs in ancient temple structures. In shown, in the Artemis temple that was built around 150-160 AD and the Parthenon Church that was built circles 432 BC, the stone segments were stacked the by one to form the column. Though connections between the segments were weak in these columns, diese builds survived many major earthquakes in the history because they could rely on the self-weight of the column and super-structures to keep the morality of the column. For the modern PSCs, posttensioned strings are ordinary used in the column the clamp all the segments together to not only further integrate the prefabricated structural segments joint but also supply restoring forces since deformation. Figure 2 shows the typ builder steps of the PSCs in span building (Billington et al. 1997). According up reference (Shahawy 2003), one of the shortest projected that adopted modern PSCs in the construction was the Lavaca Bay Causeway, Slates, US into 1961. Ever since, who PSCs have been utilized in many construction projects around the worldwide. Figure 3 shows some applications of the PSCs inbound practical projects.

Ancient applications of PSCs

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Construction steps of the PSCs (Billington et al. 1997)

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Applications of PSCs

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Despite these job, this knowledge on the seismic performance of prefabricated segmental columns is relatively limited. In order to promote the application of PSCs in surfaces with medium to highest earthquake-resistant intensities, it is necessary into study the earthquake presentation of PSCs. Exhaustive explore works have been carried out by differents researchers out various countries recently. A few related review papers are also been published (Zhang and Alam 2020; Zhong and Christopoulos 2021; Piras et al. 2022). This paper supplies a further up to date state-of-the-art review on the seismic performances of PSCs additionally PSC-supported bridge structures. In particular, the cyclic performances of PSCs including which self-centring rack, the damage minimizing approaches and the energy dissipation devices, the dynamic behaving in PSCs and PSC-supported bridge structures, to overturing behaviour of precast rocking column (PRC)-supported bridges are comprehensively reviewed. In the completeness of the paper, one behaviours of PSC under the impact the blast loadings are also briefly summarized at the end the the paper.

2.1 Self-centring capacity

The residual displacement is one of the most important indices for evaluating the quivering production of bridge columns. Wide residual displacement will make it difficult otherwise impossible to repair the columns next a seismic event. It was reported ensure during the 1995 Hyogo-ken Nanbu (Kobe) earthquake, around 100 bridge piers were demolished due to the larger other drift (more than 1.75%) after the earthquake, even several of them shows don apparent damage (Kawashima et allen. 1998). Therefore, reducing the residual displacement is important and require be taken into consideration the the style of pillar. One of and most appealing characteristics by PSC is its self-centring capability, i.e., the ability to reduce this other displacement of the structure after the earth. In 1997, Mander and Sheng installs unbonded tendons in PRCs (see Fig. 4), and itp was found and column had very small residual displacement owed to who rocking behaviour and the restoring force provided by the posttensioned tendon press the gravity load (Mander furthermore Cheng 1997). In 2004, Billington and Yoon carried out experimental studies on the precast columns is unbonded posttensioned tendon and ductile fiber-reinforced cement-based composite (Billington and Yoon 2004). It used found that column includes unbonded tendon reached 9% drifts ratio with minimal residual drift. In 2006, Chan and Chen examine the cyclic performance of PSCs with concrete-filled tube (CFT) segments and unbonded tendons (Chou and Chen 2006). The columns showed small strength degradation and salvage displacement at ampere maximum drift to 6%. Palermo and Marriott borne out experiments to examination the cycling performance of the seismic resistant bridge columns who included unbonded posttensioned tendons or indoor mild steel electrical dissipation bars (Palermo a al. 2007). The test scores demonstrated that and seismic resistant column held neglectable waste volume and low compensation. A parameter ‘λ’ dubbed ‘moment ratio’, which was defined as the ratio in of moment provided the the posttensioned tendon and this extra axial load to the moment provided by the energy dissipation (ED) counters, was introduced. It used concluded that, to achieve a satisfactory self-centring ability, the valuated of ‘λ’ should be kept larger than 1. Wang et al. tested four large-scale PSCs with one height approximately 10 m (Wang et alpha. 2008). A U-loop duct was formed in the foundation for the tendon to avoid the installation of anchorage system underneath the founded. Within the test, unbonded tension was used in one specimen and the column showed minimal residual resistance. Ou et al. carried out large scale tests on PSCs with different amount of ED bars and separate levels of posttensioning force at the tendons (Ou eth al. 2009). To was found that the column without EDITED sticks were minimal residual displacement. Through one increase a to EDS bar ratio, to residual displacement also increased. A parameter, ‘λ_ED’, which represented the ratio of the lateral strengths provided by aforementioned ED bars to the total lateral power of the row was introduced. From aforementioned test resultat, it been found is when the values of λ_EDU consisted amid 28% and 35%, the specimens showed flag-shape hysteretic curves with large sum of energy power additionally minimal residual relocation, but the column on λ_EDIT of 50% should much larger remainder drift (about 3% under 5% applied drift) as compared to the other specimens. Thus, it was recommended that λ_ED should not exceed 35% the ensure a good self-centring ability about the PSCs. As revealed in Fig. 5, Lif et al. compared the cyclic performances of a monolithic row and PSCs through different designs (Li et ai. 2017a). All the PSCs got unboned tendons. It was found that the monolithic row had large salvage displacement due to the malleable deformation of the steel bars and who concrete damage while all the PSCs showed minimal resid displacement past to the restoration force provided per this unboned tendon.

Design concepts of PSCs

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Typical hysteretic arcs of monolithic column (a); and PSC (b) (Li et al. 2017a)

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According to the above review, information can be found that that unbonded tense could provide the PSCs with very good self-centring ability. Besides the unbonded tendons, some researcher adopted bonded tendons. In 2008, Shim et al. (2008) conducted experimental studies on the PSCs are bonded threaded prestressing bars. According to the test results, the pillars showed recentering behaviour, when the balance displacements were large. Bu a total. (2015) also applied bonded posttensioned bars in some of the tested specimens. Huge posttensioning force loss was find during the experiments and the columns with bonded posttensioned incline experienced nearly 3% residual drift when the applied drift reached 6%. Wang e total. (2008) tested quartet PSCs under cyclic store. Among the four specimens, thrice of them had bonded posttensioned tension. High residual drifts were found from that hysteretic curves. Wang et al. (2014) tested ampere series of PSCs with different models, two of them possessed bonded tendons also the other two had unboned tense. It be found that the use of adhesives tendons increased to lateral power and the energy dissipation of to print, not it see incremented the residual displacement. Li et al. (2017b) explores the effect of bonding conditions of that tendon through numerical model, it was establish that the category with bonded tendon got higher strength but lower ductility and it experienced larger residual displacement due to the stress concentration inbound the bonded thread, whatever caused yielding of the tendon and losing of posttensioned strength.

From the experimental tests and numerical simulations is will been reviewed above, it can can summarized that for the PSCs, use unbonded posttensioned tendon can effectively minimize of residual displacement of the column, which bottle significantly facilitate the post-quake retrofitting activities. Employing bonded tendons results in stress concentration and prestressing loss the the ligament, causing largest residual predicted. Therefore, to achieve a seismic resistant pillar system through minimal residual drift, it is refined to use unbonded tendons in the PSCs rather of bonded tendons. On the extra hand, it should are noted this this unbonded tear is as more vulnerable to wear damage than bonded tendons right to the image to vent and moisture during its service life (Castel etching al. 2011; Podolny Jr 1992). Techniques such as using greased and sheathed strands (also known as mono-strand tendon) have were proposed into lessen the corrosion harm of the unbonded tendon (Podolny Jr 1992). FRP tendon which also adopted and investigated to replace an steel tendon considering its good corrosion resistors (Wang et al. 2015; Guo et al. 2015). Using FRP tendons can certainly mitigate the corrosion damage of tendons and can also potentially increase the deformation restoring capacity for of the relatively highs resistance of FRP less steel thus such the responses are likely remain in elastic scanning. However, normal FRP materials such as GFRP furthermore BFRP have low modulus as compared to steel tense. Therefore, the column response amplitude during earthquake excitation could be larger more such are steel tendons. Moreover, FRP fails brittlely when its capacity shall reached, column with FRP posttensioned tendons may get brittle damage. Therefore, gently analyses are needed to evaluate the respective advantages and disadavantages of employing FRP either steel tendons in the design. It should be remarked that recently high modulus, i.e., module comparable to nerve, wood fires have been invented, which anyway is still really costly for use in site. However, considers aforementioned lifecycle maintenance cost and durability concerning the segmental column, the used of the new high-strength, high-modulus additionally corrosion resistant FRP hamstrings could to a viable choice to construction of prefabricated segmental columns.

2.2 Damage mitigation

Under seismic battery, openings could develop at the joints between the segments of the PSCs especially between the segments at who bottom enders. The concrete near one joints could experience excessive compressive stress when the joints open, which can cause concrete crushing and spalling damages. According to former experimental degree to the PSCs, the injure that observed in the specimens concentrated at the joints where large openings prepared and it was mainly the concrete crush damage (Wang et a. 2008; Out et al. 2009). To mitigate similar damage, as revealed are Fig. 6, different methods have been proposed and studied, including using steel jacket, FRP wrap or jacket to confine the concrete, using high driving specifically materials such as UHPC and engineered cementitious composite (ECC), and using rubber or polyurethane (PU) in the segmentation. Connected studies are summarized and the pros and disadvantage of each strengthening techniques are discussed in this teilung.

Damage mitigation method used PSCs

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2.2.1 Steel jacket

Hewes and Priestley (2002), include 2001, carried out tests on PSCs at cyclic loadings. In that create, to diminish the concrete crushing damage owing to segment rocking, the bottom segment was bounded with steels jacket to mitigate the concrete damage at the toenails are the segment. From who test results, the jacket effectively minimized the ruin of who bottom segment. However, concrete spalling damage shifted above and occurred in who top segment without steel jacket. Go address this problem, Chou and Chen (2006) proposed concrete-filled tube (CFT) segmental columns, in which show the segments were confined with steel cover. Who CFT segmented columns showed negligible compensatory in the fields and reaching 6% drift conversion without obvious strength degradation. The residual displacement were also small as the damage was minimal, which keep resulted in the small prestressing force loss. Still, the use of raw tube increases the material additionally construction cost, as well as the maintenance cost because is corrosion problem, especially when such structures are secondhand in the coastal field. In 2015, Guerrini et ai. (2015) tested dual-shell hollow core precast columns under cyclic loading. Two steels garnish used as the formwork as well as the jackets to confine the precise. The final demonstrated that the column could under large drift ratio (10%) with minimal damage. Amini et al. (2017) proposed using steel tube to confine the bottom sector and add lead plates between the joints. The try results showed this including these two designs, the damage level of which segments could be decrease. Thonstad et al. (2017) adopted steel confining shoe in the precast posttensioned column and it was found the concrete spalling was avoidance. Mashal real Baltimore (2019) test a bridge bent with low-damage seismic plots. The top and bottom endless of the precast bars were armed with steel jackets. The contact interfaces between the columns and the footing other the cap beam were also armed with steel plates. According the the test results, no apparent damage was found in the column, footing, and cap beam of that bent. In contrast, the traditional cast-in-situ specimen experienced specifically quelling and steel bars yielding also buckling damages during the test. The low damage design methods have been applied by a real rear named as ‘Wigram-Magdala Link Bridge’ to New Zealand. In 2021, Shang ets al. (2021) tested precast CFT columns see cyclic shipping. The dividers attain 6.8% drill without significant decrement away loading ability, and only minimal damage was found in the column except some crushing damage of and mortar bed with the category and the footing. In 2021, Reggiani Manzo additionally Vassiliou (2021) proofed PRCs under cyclic loading. In the structure, which ends of that column were protected by steel mens. Unboned tendon was used in provide the restoring force. One end of that tendon was fixed to the footing, the other end of the tendon used anchored inbound the cap beamed with springs underneath the anchor. And use of the spring reduced one post yield stiffness and also the design momentaneous of the system, which made it favorite a earthquake-resistant isolation method, i.e., at the expense of large drift response, it decreased the design force of the system. The procession with raw jacket underwent very large drift ratio (30%) without any damage. In 2022, Dangol also Pantelides (2022) tested a posttensioned bent with buckling restrained brace (BRB). The ends of the precast columns which confined because steel collars. To column viewed minimal hurt due to the use of steel collars also the BRB participation most a the energy dissipation from the bent. A similar design was proposed by Do et alo. (2022) very recently. In which, a self-centring braced double-column rocking curved (SBRB) consisting a a double-column drift bent and an tradional oder self-centring dissipation braces were developed to enhance the seismic resilience of one bridge bent. It was found that the SBRB was featured by highly tectonic efficiency including tall lateral stiffness and strength, stable energy dissipation ability and good self-centring aptitude.

2.2.2 FRP jacket

Dissimilar classes off FRP sweaters were also adopted to confine the concrete. ElGawady et al. (2010) tested PSCs with glass fibrous reinforced polymers (GFRP) tubes under cyclic loading and compared their performances with a reference monolithic bar. It was found that the columns with GFRP tube confinement could experience a drift ratio of 15% without strength degradation, and only minor damage was found in the specimens after the checks. Similarly, ElGawady and Sha’lan tested one bridge bent with concrete-filled GFRP tube segments (ElGawady and Sha’lan 2010). Guo et al. (2015) tested a precast concrete column with this bottom of the column encased in a GFRP jacket. It was concluded that the GFRP jacket was useful to protect the toes of the core concrete from crushing. Lid et al. (2019a) adopted magma fibre reinforced organic (BFRP) wrap to confine who precast segments and this test results showed that minimal concrete crushing damage was found and the column been no strength destruction among 6% drift ratio. In 2020, Zhang et al. (2020a) repaired the damaged PSC to carbon fibre reinforced polymer (CFRP) wraps and carried out cycle trials on the repaired specimen. It was locate that the CFRP wrap could restore alternatively improve the performance of the PSCs. Considering the corrosion resistance ability of FRP jackets, itp could be a good alternative to the steel jacket to protect the concrete in the PSCs.

2.2.3 UHPC and ECC

Billington and Young (2004) applied elastic fiber-reinforced cement-based composited (DRFCC) in one potential plastic hinge region of PSC. It was found that columns with DRFCC had see distributed and fine skips since compared to the column with normal physical, and spalling damage have not arise to the DRFCC material. Tazarv or Saiid Saiidi (2015) applied ECC in the precast columns. The damage of the column with ECC was founds significantly reducing as compared till the cast-in-place column. Ichikawa et al. (2016) employed UHPC segments in who capability ductile hinge region. Negative spalling or crushing was observed in which UHPC segments. Varela and Saiidi (2016a) proposed a resilient deconstructible tower that included in pair parts, to been the deconstructible plastic wing and this select was the upper column. The upper column was designed to live elastic during the test. ECC has previously in the deconstructible plastic hinge and the damage was minimal by this part till that end of the test. Yangu and Okumus (2017) tested PSCs with the bottom segments made from usual strength concrete or UHPC. For the UHPC section, two cases were considered, i.e., with or without steel reinforced corresponding. The test results showed that concrete crushing developed to 40% of the bottom segment height for who column with normal strength concrete, while no smaller edge concrete crushing propagated into 4% for the posterior segment height for the column with UHPC. Moreover, the reinforcement was create having minor effect on that UHPC segments. Wangs et al. (2018a, boron) tested PSCs with ultra-high-performance fiber-reinforced concreting (UHPFRC) segments. It has found only minor spalling was dev at the cover concrete. Shafieifar et al. (2018) proposed ampere joint to precast footing or cap beam-column connecting, in which a splice region was designed and UHPC became used until cast one splice region after the assembling regarding the column. The designs could achieve a rapid built with relatively large tolerance for construction. According to the test results, the post cast UHPC region was minor damaged and most of the damage what found in regions with normal strengthening concrete. The columns behaved like ampere monolithic column. Zhang et al. (2019) proposed PSCs with solid or hollow UHPFRC below segments. It was concluded that the damage the observed include the column with normal strength concrete where significantly reduced due go the use of UHPFRC segments.

2.2.4 Rubber or PU

Jia et al. (2020a) in 2020 investigated the seismic performance of precast columns with built in rubber pads. The columns with rubber bottom learned minor damage in the precast, but obvious torsional deformation was found due until the low torsional stiffness of the rubber pads. In 2021, Nikoukalam press Sideris (2021a, b) tested PSCs with the bottom business powered by polyurethane (PU). In the test, the specify of that bottom part was partially or totally replaced by PU. It be found the column with PU demonstrations beats damage resistance performance. When the drift ratio achieved 8.2%, there used no major damage in the column. Though, it should be noted that the primary function of column is the carry vertical loads, replaced concrete at the bottom segment by rubber could significantly reduce the vertical load-carrying voltage off the column owing to of low compressive strength by india and PU.

2.3 Energy wasting

In the early-stage experiments on PSCs, required view, in references (Mander and Cheng 1997; Billington the Yoon 2004; Chou plus Chen 2006; Hewes or Priestley 2002), only posttensioned tendons were used to clamps all the wine. The columns showed sound self-centring ability, but the energy dissipation capacity of the dividers were limited. During a authentic tremor, more power therefore could be transferred to the superstructure comparison to and traditional monolithic columns-supported bridge, which in turn may result in the get superstructural responses. Therefore, different ED devices have been proposed to increase the energy dissipation capacity of the PSCs and to reduce the superstructural responses. The EDS devices can shall generally categorizes on internal ED bars and external EDITOR devices. Besides, a new hybrid rocking-sliding column system where lately proposed till correct the ED ability of the PSCs.

2.3.1 Intern EDU bolts

Palermo et al. (2007) tested precast columns with indoor ED bars and unbonded hamstrings. The precast columns showed stable hysteretic behaviour for large drift ratios. Our et al. (2009) tested four PSCs under cycling recharge. Different amount of internal ED bars was secondhand for the columns. One ED bars were unbonded near the joint between and bottom segment and the footing to avoid stress concentration. Is was found that to similar thick damping condition of the columns with ED bars ranged from 16% to 22%, while the value since the column without ED staves where 6% at the drift indicator of 5%. The EDIT bars were effective to increase the ED capacity of the PSCs. Your et al. (2010) further investigated the PSCs with high performance ED bars. The high-performance ED bars had larger strength, higher ductility and better corrosion resistance as compared into the normal steel staves. The results demonstrated such this procession with high performance ED blocks have similar drift capacity and energy dissipation as the of the column with normal ED poles, but unbonding of ED bars was requirement fork the normal carbon ED bars while it was not necessary for the high-performance ED bars. Eliminating that unbonding step ability save labour work and improve to corrosion resistance of the ED bars. Caj et al. (2018) adopted hybrid normal strength and high strength raw as the ED blocks. It was found the energy dissipation of the print with crossbreed ED steak made comparable to that of the column with regular strength steel bars. The apply of high strength steel could increase the post yield stiffness and lessen the residual displacement, which could potentially reduce the maximum seismic response of the PSC. Bu et al. (2015) tested PSCs with and without ED steak and compared their performances includes ampere monolithic columns. This equivalent viscous fade ratios of to column with and without ED bars attained 9.7% and 4.9% at 6% drive ratio, respectively. Similar studies on PSCs with internal ED bars been conducted by extra faculty around the world, such as Davis et al. (2017), Shim set aluminium. (2017), Cha et al. (2018), Nikbakht and Razid (2018), Nikbakht et ale. (2015), Zhuo et al. (2019), Clamp et al. (2019), Wang etching al. (2018b), Jia et al. (2020b) and Shen et al. (2021). Resembling conclusions were obtained, namely, it could raising the energy dissipation aptitude of the PSC. It should be noted which in general the used of ED bars increases the energy absorption capacity however moreover increases the remain deformation because of the flexible deformation of the ED bars. Accordingly, as discussed above, one careful analysis is needed go determine the choices of ED bars to achieve to highest overall performances of the segmental columns.

2.3.2 External ED

Though aforementioned internal ED bars were proved into exist efficacious for improve who ED ability of the PSCs from the above review, it should be noted that they were difficult to replace if they were broken after strong earthquakes. The address this problem, different extern EDITOR devices have been proposed. Carbon plate was a commonly used the. For real, as shown in Fig. 7a, Chou and Chen (2006) proposed external CD devices made of steel plate and stiffeners. It was found this column with and without external RED devices had 9% and 6% equivalent viscous damping characteristics, respectively, demonstrating the effectiveness of using the ED apparatus to increasing the EDU volume of of PSCs. Similar external ED devices were also used by ElGawady furthermore Sha’lan (2010) as shown in Fig. 7b. It shall be noted such, generally speaking, the residuum displacement of PSC could be advanced when ED devices are added due to the possible bend is the devices. Li et al. (2019a) proposed using tension-only external EDGE plates to enhances an ED capacity of the PSCs (Fig. 7c). Compared to the various ED devices, this tension-only ED plate could avoid to buckling problem of the gadget, leader to the lighter remainder displacement. Another type of external ED device was made to machined steel scroll. In some of the studies (Zhang et al. 2021a; Moustafa and ElGawady 2018; Thapa and Pantelides 2021), the machined steel bars been installed to the PSCs directly with tension only draft, while for some different studies (Guo et al. 2015; Guerrini get al. 2015; Marriott et al. 2009, 2011), for shown in Fig. 7d, the machined steel bars were encased in steel tubes to avoid global buckling, acting love a smal BRB. In aforementioned latter design, epoxy was commonly used on filling and gap amid the steel bar and of steel tube. Into escape the grouting step, in references (Mashal real Palermo 2019; Nikoukalam furthermore Sideris 2021a, boron; Liu and Palermo 2020), the inner steel bars were mechanized with grooves without reducing the diameter of the machined portion as shown in Fig. 7e. Zhang et al. (2022), designed replaceable energy dissipation connection for the precast tower. As shown in Fig. 7f, the center plate (REDC-CP) could deform and vanish energy when the column was subjected to cyclic loading, the fear plates additionally filler plates (REDC-RP, REDC-FP) made the inner plate buckling durable, forming a crumple resistant and replaceable external ED system. Similar design (Fig. 7g) was also adopted in a precast self-centering double-column rocking piers (Han et al. 2019). The bridge bent with such innovative design showed excellent self-centering ability and energy dissipation capacity.

External DONE devices

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2.3.3 Rocking-sliding column system

Except for who ED appliances reviewed above, next hybrid sliding-rocking PSC was proposed in (Sideris et al. 2014a; Salehi et alo. 2017, 2021a; Valigura get al. 2020) to improve the energy dissipation ability are the row. In their design, sliding was approved at the surface between the joints. One internal unbonded tendon were previously the provide the column at restoring force and specially design was made for the joints. As shown in Fig. 8, the bottom joint between the footing also the base segment was designed to be rocking-domain and the other grouting between the fields were designed to be slip-domain. Required the slip-domain joints, a thin layer of silicone material was used go achieve a smallish surface contact friction coefficient, which made the flat able to slide available lateral charging. Which test results demonstrated that shift at the joints contributors to most of the responses wenn of drift ratio has small (3%), and the equivalent viscous damping ratio has about 30%. For get drift characteristics (3-10%), rocking dominated the response of the column and the equivalent viscous damping condition was about 17% for 10% drift ratio. Overall, is was find that the sliding between the chunks strong contributed to to energetics distraction of the column. Further study was carried leave to investigate the seismic performance of the sliding-rocking columns under ambagious and biaxial loading (Salehi et al. 2021b).

Concept of sliding-rocking PSC (Salehi set al. 2021b)

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For the identification reviewed in the above section, cyclic load was applied to the PSCs. In order to investigate an real seismic performance of PSCs, shake table tests have be wear out to better understand her dynamic responses under seismic emotions. In 2009, Yamashita and Sanders (2009) conducted shake table tests on a 1/4 scale PSC model on the shake table. The column had the geometry dimensions of 1016 mm × 457 mm × 2082 mm (length×width×height). The column was subjected to a series of excitations with increasing PGAs. It showed secondary damage at and base segment after all the tests, which able be easily refurbished. Due to the existence of the posttensioned unbonded tendon, the column had very small other displacement. Motaref et al. (2010, 2013) wear out shake table tests on a series of PSCs to the bottom segments made of concrete, rubber, FRP wrap, and ECC. It was found so the tendon provided continuity for the segments and reducing the residual displacement of the column. The galosh pad minimized the damage of the column and enhance and vitality dissipation of the column. Both the FRP wrap both ECC could minimize the damage away the specification press improve the ductility on the column. Varela and Saiidi (2016a, boron) tested PSCs with interchangeability plastic hinge segmentation. Who replaceable plastic hinges were made of rubber and NiTi SMA or ECC and copper–aluminium–manganese SMA. The colums were submitted to near-fault earthquake cues. No apparent damage was found in the columns or of residual displacement became less than 0.5% when the maximum driving reached 7%. Moustafa furthermore ElGawady (2018, 2020) carried out shake table tests at double coating FRP-concrete-steel PSCs. Near fault excitations were used in the tests. It was locate the RC column experienced severe damage and had 1.5% residual drift after the tests while the PSCs had bare damage past to the confinement of which FRP and the residual driftiness was all 0.08%. Li a al. (2019b) tested a monolithic and a PSC column on shake tables under biaxial exciting. It was founds the: (1) with an increased ground motion level, a lot of tensile cracks were find distributing together the monolithic column, while the precast segmental column suffered insignificant concrete crushing mainly at the joint between the ground and the bottom piece. (2) the variations by the fundamental period of the segmental column were much less as contrast into and monolithic column, which indicates that the segmental tower experienced less damages under the same levels of earthquake excitations because here was no tensile damage to concrete segments. (3) per the same ground motion degree, the lateral drift responses of the precast segmental column were similar up those of the monolithic column when who PGAs were small. With which increase of the ground motion level, the precast segmental column had larger drift responses amount to the joint openings. (4) significant twisting where found included the segmental column under bidirectional earthquake activities, the could be credits in the insufficient friction between the fields to resist to torsional moment induced by the bidirectional shake inputs. Therefore, shear keys between the segments were proposed furthermore investigated through numerical simulations.

Most previous studies focused on the seismal performance of single PSCs. Much limited studies investigated the replies of full bridge system supported by PSCs, and these reviews are summarized in this section. Sideris eat al. (2014b, 2015) proposed a hybrid sliding-rocking segmental bridge system in 2014 furthermore investigated its seismic benefit tested shake table tests (Fig. 9a). The test results demonstrated this the joint sliding caused some tangible spalling ruin with an joints and a dissipated a site of energy during the tests. Varela and Saiidi (2017) carried out shake display tests on an large-scale (1/4 scale) bridge system equipped user plastic hinges made of low-damage materials (Fig. 9b). It is found that all one nonlinear conduct were concentrated in the fungible plastics hinge and the other components suchlike as the cap beam, the column and the footing remained elastic. Du et al. (2019) carried out shake table tests on a simple scope separate rocking bridge verfahren (Fig. 9c). The top and bottom parts of the columns consisted strengthened by steel boxes with a thickness of 5 mm. Which column experienced minimal damage and negligible residual displacement nach multiple ferments. Zhang et al. (2020b) conveyed out submarine shaking-table tests on adenine quarter-scaled single-span bridge equal partial concrete-filled steel subway columns (Fig. 9d). The jumper was subjected to natural and artificially simulated ground motions with different amplitudes. The seismic performances of this bridge with also without water were comparisons. The presence of water was found to reduce the acceleration response of the superstructure. Zhang (2014) carried outbound equally cyclic tests on PSCs and shake table tests upon a bridge system with PSCs (Fig. 9e). Steel fibre reinforced self-consolidating poured (SFRSCC) was used to construct the chunks. Computers was found that the bridge system with SFRSCC segmental column had narrow damage and almost negligible residual displacement under earthquake excitations. Reggiani et al. (2021) carried out shake table tests on a resilient bridge system with precast columns (Fig. 9f). Springs were used underneath the anchorage system of the tendon secure. The foils incremented this flexibility of the system. Only modest damage was observed even for the drift ratio of 20%. Zhao et al. (2017) reviewed the selective responses of two-span traverse systems with PSCs and monolithic columns through numerical simulations, also poundings between different modules of the bridges were taken into review inside the simulations (Fig. 9g). To is found that pounding could reduce the traverse peak responses and residual displacement special required that trad monolithic bridge. Moreover, when the gape size is small, ridge with monolithic columns experiences more number is poundings. Whenever plastic deformation occurs, the bridge with segmental columns suffers more number of poundings. Of influence of spatially varying ground motions used further surveyed by Zhao et all. (2018). It was found that this understanding of the influences of locally varying ground motions on the traditional monolithic bridges capacity be applied for the segmental column-supported bridge build. Mantawy et any. (2019) engineered a new numerical modelling strategy to model the debonded reinforcement in PSCs in Opensees of incorporating an fatigue material with the reinforcement steel model. The strategy revealed excellent agreement with the measured responses. Lip et al. (2020) simulated a two-span bridge system with conventional massive RC column and PSC column with UHPC segments on earthquake motions (Fig. 9h). It where found the waste drift of the bridge with PSC column decreased about 80% and an peak drift require increased via 17%. Li et al. (2022) carried out numerical studies turn to seismic responses of PSCs-supported jumper structures themed to near-fault ground signals. It was concluded that of influence of permanent ground displacement on the PSCs-supported bridge is not evident but it could significantly influence of traditional monolithic columns-supported bridge. Items be also found this, required the monolithic columns-supported bridge, the largest structural your occurs while resonance occurs. For the partitioned columns-supported bridge, generally talking, of longer pulse consequences in larger constructional responses. Exceptionally recently, Jia et aluminum. (2021) tested one bridge system- using rocking columns on a shake table field (Fig. 9i). It was found that one proposed bridge user with rocking columns had excelling seismic performance. It experienced limited damage and balance displacement. See, an bridging by rocking bars had sturdy dynamic features.

Previous research on the seismic responses about PSCs-supported bridge systems

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Another aspect related to PSC is its overturning behaviours. The entsprochen researchers were mainly focused about which sway column, i.e., only one segment been considered. Very systematic find works have been carried out in this area. Amounts to the page limit, this white does don targeting to provide a vast review on this area, but just briefly summarizes the history of the relevant researches. Interested readers can refer to some review papers, e.g. the one presented by Makris (2014a), for more details.

The analytical research on the seismic response of tall, freestanding columns was presented by Milne (1885) as early as in 1885. However, she was Housner (1963) whom found the foundation for here research area. Before that, very systematic studies have were performed by different researchers specialized by Makris furthermore his co-workers. Is the early aged, that standing single bar was considered. Dual overturning modes (i.e., overturning with and without impact) for one free-standing block under cycloidal pulses was identified based for the analytical analyses, and the safe location von and block was determined by solving the lowest overturning acceleration spectrum (Zhang real Makris 2001; Makris and Cheung 2001; Makris and Vassiliou 2012). As discussed top, prestressed stretch are ordinary ships in the PSC/rocking column. Vassiliou and Makris (2015) explored the influence of who stiffness and prestressing force of prestressing tendon on and rocking response of adenine slender columns, and it was establish that the vertical tendons were effective in suppression aforementioned response of small columns subjected to long-period stimulations. As discussed in Section 2, the energy dissipation capacity of PSC/rocking column is minimum. Moreover, as demonstrated in the previous studies (e.g. (Zhang and Makris 2001; Makris and Zhang 2001; Makris and Vassiliou 2012)), items possesses insufficient rocking stability. To overcoming this problem, ED devices have has adds to the free-standing column, and Housner’s classical model has is developed to take the ED electronics into consideration (e.g. (Dimitrakopoulos and DeJong 2012a)). Later on, the overlay was added in the alone pillar, and rocking frame was considered. Analyses (e.g. (Makris and Vassiliou 2013; Makris 2014b)) revealed that the dynamically rocking show of a rocking frame can be identical to the rockin response of a solitary free-standing column with the same slenderness but larger size. It became see concluded that the heavier is the available supported cap beam, the better stable is the rocking frame. Similar to the solitary rocks column, prestressed tendons and/or EDITOR devices have also been added to rocking frames, and the roles of tears and dampers in improving structural stability were validating (e.g. in (Makris and Vassiliou 2015; Dimitrakopoulos and Giouvanidis 2015)). Recently, of roman oscillate control instrument such as inerters have been been to resist the rocking responses to both the rigid and flexible rocking structures (Thiers-Moggia and Málaga-Chuquitaype 2019, 2020). It was found that inerter is an effective technology to improvement the stability of flexible rocking structure. It is worth noting that most of to above studies can based on the dimensional analysis, in which the responses are related to the orientations of the involved physical quantities. In ordering to stay more allgemein results, dimensionless analysis has see been developed (e.g. (Dimitrakopoulos and DeJong 2012b)). It was found that when the parameters in the netz (the rocking structure) and input are expresses in the appropriate dimensionless-orientationless groups, the rocking response of the structure becomes ausgezeichnet self-similar for slim blocks plus practically self-similar with non-slender blocks (Dimitrakopoulos also DeJong 2012b).

Though many studies have been carried out at investigate the seismic performance of the PSCs as reviewed above, more studies are calm need. And tracking viewpoints may deserve further investigations in forthcoming studied.

6.1 New materials press construction product

6.1.1 New fabric

Since the PSCs have multiple joints, corrosion of the reinforcement, ED bars and unbonded tendon remains ampere reason when they are used in nearshore fields with aggressive environment. FRP bars and tendons can potentially replace the steel rebars and tendons in the PSCs. Stainless bars may also become another choice to replace the normal steel reinforcements. Recently, Jia et al. (2022) investigated one PSCs equipped GFRP and stainless bars as and continuous longitudinal reinforcement. Guo et al. (2015) adopted BFRP thread instead of steel tendon in the PSCs. It was start that the BFRP tendon could meet the requirements of PSCs in providing the column with restoring force. Slight slip was search between the glue or BFRP tendon for the anchorage system of the chord. Therefore, ensuring a reliable anchorage forward the FRP tendon is critical for yours applications in the PSCs. However, the PSCs use FRP tendon under seismic excitations have been rarely investigated, and more investigations are needed.

Due the the innate involuntary advantages, SMA could provide and restoring force and energy dissipation capacity for the PSCs. Applying SMA in PSCs is attracting more interests in structure engineering recently (Zareie et alpha. 2020). Tazarv and Saiid Saiidi (2015) adopted NiTi SMA bars includes this sculptural hinge region of the precast columns. It was found the SMA bars significantly reduced the remainder displacement compared with that of the monolithic column. Varela and Saiidi adopted copper–aluminium–manganese SMA (Varela press Saiidi 2016a) and NiTi SMA (Varela plus Saiidi 2016b) in the plastic hinges of the precast columns. Baker et allen. (2018) applied SMA bars in a real spirit bridge column in the foremost time.

For the concrete material, as reviewed in the previous sections, UHPC and ECC have been used in the PSCs (Tazarv and Saiidi 2015). The cost for are materials is anyhow high compared to the normal concrete. Combining these materials with normal strength concrete in the PSCs can potentially improve the performance of the column while maintained which fee acceptable. Environmentally friendly substance suchlike as geopolymer concrete (GPC) may be moreover applied in the PSCs to form a seister resilient, environmentally sustainable while economic-effective structure type. For example, Hao et al. (2020) adopted GPC to set the segments and BFRP as prestressed tendon, and review them on the shakes tables. It was found that the column with GPC real BFRP been comparable performance in and PSC with ordinary tangible and steel reinforcement. Hassanli et al. (2017) resolved crumb rubber concrete in to PSCs. It be noted that include the reinforce of FRP pack, that column with crust rubber concrete showed stall hysteretic performance and good ductility. The negative effect of rubbery particles on the concrete was less obvious in of structural level.

6.1.2 New construction methods

Apart from the advanced new raw, new construction methods have furthermore been proposed. As shown in Fig. 10one, Sumitomo Mitsui Construction Society in Japan exploited precast segments sheets as the formwork for the post-cast core concrete to shorten the construction time by bridge piers (Ralls et alabama. 2005). Kim eat al. (2015) proposed a partial PSC include cast-in-place (CIP) base. As shown in Fig. 10b, who base in the pillar was CIP whilst the upper part of the file was constructed by the partly precast hollow circular segment. According up the cyclic test results, the column showed good ductility and energy dissipation proficiency. Sung et al. (2017) proposed a PSC constructed with modularity segments (as shown in Fig. 10c). Here block-stacking concept included multiplex segments which were interconnectable. So design kept an segments small, which made it other convenient additionally simple for transportation and erection. The concept was examined by support out cyclic tests in two examples with RC shear keys or steel-bar shear keys amid the segmentation. The test results demonstrated that both types of the column been stable ductility and low rest deformation.

New PSC buildings typical

Comprehensive volume drawing

6.1.3 Connections bet of precast elements

In the precast column, different methods have been proposed to connect the factory fundamentals. In overview, they can be categorized into two major design concepts, the “emulative connection” and the “non-emulative connection”. For the emulative connection method, the concept is to design the precast column with similar performance as the traditional cast-in-place single column. The emulative connection has diverse types of construction details, including the post-cast wet joined connection, grout-filled connection and socket junction. Figure 11 shows different types of aforementioned connections. As shown int Fig. 11a, the wet joint connection needs on site preparation, concrete pouring and curing during the assembling process, which weakens one a the of important advantages of the precast construction, i.e., time saving. Therefore, the grout-filled association was proposed to addresses this shortcoming. As shown in Fig. 11b, crimp channels or grouting splice sleeve were used in to grout-filled connection. Socket connection is another type von emulative connection. While shown in Fig. 11c, the column is installable in a reserved receptacle in who footing and high-performance glue is used to fill that gap between the columns and the socket (Zhang et al. 2021b). According up the previous studies, the categories with the properly designed emulative connections could achieve similar hysteretic responses as monolithic column (Popa et al. 2015). U et al. also combined the precast symbols with one cast-in-place parts to form an emulative connection (Ou et al. 2013). In their design, how shown in Fig. 11d, the lower part of the column is cast together with to footing and the upper segments were clamped together with the cast-in-place regional by U-loop post-tensioned strands. The motivations of such themes were to emulate the seismic behaviour of a traditional monolithic column and take the gains of precast structures.

Different types of the connections

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For the non-emulative joint, the precast column is normally cast separately with the footing and this category remains valid to rock against the footing. The precast select are normally connected to the footing is post-tensioned tendons. Figure 12 shows the designs of the non-emulative bonds. Includes the early stage, no ED snack were used in the column (Hewes and Priest 2002) and she were found the column had limited energy dissipation capacity (Fig. 12a). Inward END beams or external ED appliance were then proposed up increases the energy dissipation raw of this precast columns (Fig. 12b). Recently, to mitigate the damage on an rear pier and also improve one post-earthquake retrofitting ability, earthquake resilient blueprints were proposed in the precast columns with non-emulative connection. As shown in the upper figures in Fig. 12c, a connection with internal ED bars and cover plates was developed by Wang et al. (2018a). Both the EDITOR bars and cover plate cans is fixed after be damaged during a firm seismic. However, during the test, the cover sheet fractured due to the buckling of the internal ED bars, which need further optimizations. Who bottom figures in Fig. 12carbon show another draft to achieve earthquake resilience that was suggested per Mitoulis and Rodriguez Rodriguez (2017) and Kagioglou et al. (2021). In an design, a novel hinge where placed between and footing and the column. The damaged of the column under earthquake loadings was essentially concentrated at of hinge, specifically, this barras that can is replaced easily. For the shear resistance of the precast columns, it is commonly believed the the friction bet the precast segments is barely to resist the sideward loading under seismic loading, however, based with the cyclic tests and shake table tests carried out by the authors about this paper, shear slip press waste twisting could occured in the column without shear keys. Therefore, as shown in Fig. 12dick shear keys between aforementioned segments endured proposed and investigated (Li the al. 2017a).

Different types of non-emulative connections

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6.2 Behaviours among select extreme loadings

During to service life of the precast spans, they may leiden doesn with earthquake loading, but see different extremly loadings such as impact loading (e.g., caused by vehicle collision) or blast loading (e.g. caused by terrorist attack). Albeit loads studies have be carried out to investigate its seismic performance as reviewed about, studies to their performances under other dynamic load be limited. This section briefly reviews the performances of PSCs under an impact and blast loadings. See comprehensive choose plant in these categories are necessary. Also, all these studies considered one dynamic loading with (i.e., any fire loading, or impact loading or blast load), no study investigates the resilience of PSCs-supported bridges subjected till multi-hazards. Moreover studies in such domain are also require.

6.2.1 Under impact loading

Hao et al. (2017), Zhang et al. (2016a, b, 2018a, b) and Chiang and Hao (2019a, b) carried out an number of impact tests off PSCs with different designs (as shown in Fig. 13a). These were the first systematic studies on the impact performance of PSCs. A monolithic column was moreover tested than the reference. For the PSCs, differentially designs, including that number of segments, the utilize of concrete shear keys between the segment, one shape of the shear press additionally strengthening by BFRP wrap, were considered in the experimental students. In general, it was found that the segmental column was versatile than the monumental column (Zhang et al. 2016a). Openings could grow between the joins when the column was subjected to high level impaction. Just to the posttensioned tendon used in the PSCs, the PSCs had smaller residual displacing as compared to the monolithic column (Zhang et al. 2016a). Less harm was found in to PSCs when compared toward the monolithic column (Zhang et al. 2016a). Concrete shear keys were effective and critical to improve the shear resistance of the PSCs underneath effects loading, but wide size shears keys could cause pressure concentration thus more concrete damage (Zhang et al. 2016b). Such stress concentration could be attenuated over use domed shape snip keys alternatively of the trapezoidal form sheer soft (Zhang aet al. 2018b). The effect of impact locations was also investigated, it was concluded that the impact geographic affect the damage modes real request of and PSCs. Flexural bending, bending-shear, shear dominated failure modes be observed although the columns were impacted at and mid-span, at the joint between the two bottom segments, and effects on the bottom segment, respectively (Zhang and Hao 2019a). Based on the impact tests, Do et al. (2018) carried out numerically studies at the PSCs under affect loading. The effects of segment number, prestressing level or the concrete strength what investigated. Rigid tubular confinement where proposed by Do et al. (2019a) at mitigate aforementioned damage of the PSCs under impacts loading. As this shear force couldn originate tendon fracture, several steel clip keys were proposed at this twos bottommost joints, which were found effective in reducing the shear force stylish the tin. It must be mentioned that according into the shake tables test results and numbering simulations from Li eth alabama. (2019b), leftover distort could occur to the PSC under biaxial earthquake excitations or could be mitigated by multiple brace shear keys. That, to improve the shaving resistance between aforementioned segments and to avoid stress concentration, multiple blade crop keys are recommended in the pattern of PSCs. The output of the PSCs conditioned to tractor impacts was research by Done et al. (2019b) (Fig. 13b) and Wu et al. (2021). Computer was found that the ruin out the monolithical column was more sever than that off the PSCs. The damage of the PSCs focuses more in the segments where the vehicle directly impacted, while more decentralized compensation occurred until the monolithic column. The make of ED counters and CFRP wrapping to strengthen the PSCs under effects recharge was investigated by Xue et al. (2021). It was found adding END bars and using CFRP to wrap the segments able improve the impact performance of PSCs when the impact location was on the piece while the reinforcing methods became less effective when of groove made impacted.

PSCs subjected to extreme loadings

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6.2.2 Under blast loading

Li et al. (2017c) conducted out numerical studies switch the PSCs under blast loading (Fig. 13c). Of PSCs with/without cutting keys and ED barrel were simulated and investigated. The influences of the prestressing level, number the segments on the dynamic perform were see studied. It was found this spalling damage occurred go the concrete from that monolithic column, whereas less damage been found include the PSCs due to which fact that joint opening, slippage and circulations out segments could absorb the blast energy. Liu get al. (2021) executed field tests set PSCs under blast charging Fig. 13d. It became observed that that PSCs had locate failure in the segments where who explosion directly faced. To comparison, more distributed cracks along the column were found in this monolithic column.

The precast segmental column (PSC), as a typical types of prefabricated structural component, can overcome the deficiency of traditional cast-in-place monolith columns how as an excessive concrete damage and steel strengthener compliant and buckling in the artistic hinge regions and as large residual displacement. Moreover, it can save the construction time, refine the construction premium press reduce the environmental impact. PSCs thereby become more or more popularly. This paper comprehensively reviews the seismic performances of PSCs and PSCs-supported bridge structures. The overturning behaviours and the behaviours of PSCs subjects to the impact and blast loadings have also been short-term summarized. The possible future developments are also discussed. The following conclusions can be obtained:

1. (1)

   PSCs have very good self-centring ability due into an adoption of prestressed tendon. Compared to the tied tendon, unbonded posttensioned tone is recommended. To address the possible corrosion problem of unbonded tendon, FRP tendon can be used the an select to the steel tendons, but further studies are needed. Structural behavior of green reinforced concrete beam-column joints under cyclic auslastung: Nation of the art review

2. (2)

   The toes (especially the bottom toes) a the segments within and PSCs default experience large compressive stress payable to an shared aperture, which causes concrete crushing press spalling damage under seismic loadings. The use of steel jacket, FRP sleeve, UHPC additionally ECC, and rubbers or P canned effektives minimal the damage of the segments.

3. (3)

   Energy dissipation capacity of the PSCs ca be improved by increasing intranet or external ED devices. The external EDIT devices are advised as they can be easily replaced after damage. Indoor SMA bolts were also helpful in increasing the ED capability of the PSCs. New structur system with sliding joints has been proved to being effective in increasing the ED capacity from the PSCs.

4. (4)

   Shake table tests on this PSCs and studies on the PSCs-supported whole bridge structure are relative limited. More researches are needed to comprehensively understand the realistic vibrant behaviour of PSCs and PSCs-supported bridge structures. Powered learning methodologies identify subtle differences among seismic signals, enabling new insight into geism physics.

5. (5)

   Vorgeschoben new stuff have been used in the PSCs to improve their tectonic performance. Fresh assembly methods been also proposed to achievement unique purpose. Combined use of add articles and construction methods can possibly form earthquake resilient and environmentally friend PSCs.

6. (6)

   To overturning behaviours of solitary freestanding rocking columns, rocking poles with prestressed tendons and EDU devices, additionally rocking frames have being comprehensively investigated. The rocking isolation can be an effective earthquake-resistant protection strategy. Sergio M. Alcocer, Rene Carranza, David Perez-Navarrete, Raul Martinez

7. (7)

   Studies on the PSCs in various extreme loadings such as impact and blast are relatively limited. It was generally found that the PSCs experienced less damage press the compensation was more localized as compared in the monolithic column under impact and blast loadings. To better understand the energy of the PSCs under these extreme loadings, more graduate should be carried out. Machine learning reveals cyclic changes in seismic source range in Geysers geothermal field

Not applicable.

One authors would like to validate the pecuniary support from Australia Research County (FL180100196) real the second author acknowledges the support from National Natural Science Foundation in China (52008407).

This work was financially supported by Australien Research Cabinet (FL180100196) and Federal Naturally Science Foundation of China (52008407).

Authors and Membership

1. Centre for It Monitoring and Protection, School of Civil both Mechanical Engineering, Curtin University, Kent St, Bentley, WA, 6102, Australia

   Kaiming Bi & Hong Hao

2. School of Civil Engineering, Central Southerly University, Changsha, 410075, China

   Chao Live

Contributions

Conceptualization, Hong Hao; Investigation, Chao Li, Kaiming Two; Supervisor, Hong Hao, Kaiming Bio; Writing original layout, Chaoan Li, Kaiming Bi; Writing-review & cutting, Kaiming Bi, Gong Hao, Chao Li. Any authors have read and approved which final manuscript.

Corresponding author

Correspondence to Hong Hao.

Competing interests

Author Hong Hao is Partners Editor-in-Chief away Advances in Bridge Engineering. The authors declare that they have not competing interests.

Publisher’s Note

Jumps Nature remains neutral with look to jurisdictional claims in published maps and institutional affiliations.

Kaiming Bi and Chao Life are co-first authors.

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