CURRENT TECTONIC ACTIVITY OF THE CANGSHAN-NISHAN FAULT AND ITS IMPACT ON THE RESIDENTIAL BUILDING DAMAGE
The NW-trending Cangshan-Nishan(Cang-Ni)Fault,extending 170km,exhibits significant tectonic deformation and seismic activity in the late Quaternary,attracting considerable attention.This study investigates the relationship between residential building damage in Guanzhuang village,Baiyan town,Pingyi county,Shandong Province,and the activity of the Cang-Ni Fault.Based on field investigations,geomorphological measurements,fault activity identification,surface structure analysis of quartz fragments in fault gouge(SEM),particle size distribution analysis,InSAR time-series analysis,historical research on the 179BC M7 Qichu earthquake,and previous earthquake damage studies,the following conclusions were drawn:1)Severe structural damage with left-lateral displacement of 0.5-2cm was observed in buildings along the main Cang-Ni Fault,with cracks originating at foundations and decreasing in scale upward.In contrast,buildings along secondary faults experienced relatively minor damage.Foundation cracks in the main fault zone were wide and numerous,propagating upwards to narrower wall fissures,indicative of structural failure.2)Damaged buildings in Guanzhuang village align with the left-lateral strike-slip zone of the Cang-Ni Fault,coinciding with the epicenter of the 179BC M7 Qichu earthquake.This area represents the hub of late Quaternary fault activity,characterized by significant displacement and recent faulting strata.3)SEM analysis of quartz fragments suggests that the Cang-Ni Fault's latest activity occurred in the early Holocene,with a combination of stick-slip and creep-slip mechanisms.Particle size analysis revealed a high proportion(36％-43％)of ultra-fine particles(＜0.001mm)and fractal dimension values of 2.817-2.857,favoring fault creep.4)InSAR data confirm ongoing sinistral strike-slip movement of the Cang-Ni Fault,indicating surface creep deformation.5)Damage to residential buildings is attributed to the sinistral strike-slip and reverse-thrust creep deformation of the fault,stratigraphic and structural differences across fault walls,uneven stress distribution,and swelling effects of fault gouge.This research provides a case study of building damage caused by active fault creep,emphasizing the importance of precise identification and spatial mapping of active faults for seismic design and site selection in engineering projects.The findings offer valuable insights for mitigating seismic hazards in fault zones.
Fault creepingground fissuresdamage of residential buildingsInSAR time-series analysisCangshan-Nishan Fault
万方数据
维普
