On June 22,2022,the Mw6.2 earthquake in southeastern Afghanistan caused a severe disaster.We used the Sentinel-1A ascending and descending track images of the European Space Agency and interferometric synthetic apertu...On June 22,2022,the Mw6.2 earthquake in southeastern Afghanistan caused a severe disaster.We used the Sentinel-1A ascending and descending track images of the European Space Agency and interferometric synthetic aperture radar(In SAR)to obtain the coseismic surface deformation field of the earthquake,which showed that the earthquake caused complex ruptures of multiple faults and various types.Using the dislocation model of the elastic half-space,we determined the focal parameters and slip distribution on the fault plane of this event.The results reveal that:(1)the seismogenic fault of this event is an unknown fault on the northeastern edge of the Katawaz microblock;(2)The slip on the fault plane is mainly in the range of 0—8 km along the dip,with maximum slips about 2 m at a depth of 2 km,which projected on the surface is 69.44°E,32.96°N.This event suggests that,similar to the Chaman,Ghazaband and other large faults,the faults inside the microblock also play an important role in adjusting for the collision stress between India and Europe.展开更多
Depths of earthquake occurrence and large slip distribution are critical for seismic hazard assessment.Numerous examples show that earthquakes with similar magnitudes,however,can result in significantly different grou...Depths of earthquake occurrence and large slip distribution are critical for seismic hazard assessment.Numerous examples show that earthquakes with similar magnitudes,however,can result in significantly different ground shaking and damage.One of the critical factors is that whether the large slip was generated near the ground surface.In this article,we reviewed two aspects that are important on this regard,shallow slip deficit and nucleation depth.Understanding how shallow future earthquakes may nucleate in particular regions,such as shale gas fields,is critical for hazard assessment.Whether or not a strong earthquake may slip significantly at shallow depths(less than 3 km)plays crucial rules in seismic hazard preparation and should be further investigated by integrating high-resolution fault zone observations,dynamic rupture simulation,and fault zone properties.Moreover,precisely resolving shallow depth and slip distribution of earthquakes demands InSAR and/or other image data that can better capture the near-fault deformation to constrain the source parameters of earthquakes.展开更多
A slip-line field solution is presented for the ultimate bearing capacity of the pipeline on a purely-cohesive clay soil, taking into account the circular configuration of the pipe, the pipe embedment, and the pipe-so...A slip-line field solution is presented for the ultimate bearing capacity of the pipeline on a purely-cohesive clay soil, taking into account the circular configuration of the pipe, the pipe embedment, and the pipe-soil interfacial cohesion. The derived bearing capacity factors for a smooth rigid pipe limit to those for the conventional rectangular strip footing while the pipe embedment approaches zero. Parametric studies indicate that, the pipe-soil interfacial properties have much influence on the bearing capacity for the pipe foundation on clayedy soils.展开更多
基金supported by the National Natural Science Foundation of China(No.41874117)。
文摘On June 22,2022,the Mw6.2 earthquake in southeastern Afghanistan caused a severe disaster.We used the Sentinel-1A ascending and descending track images of the European Space Agency and interferometric synthetic aperture radar(In SAR)to obtain the coseismic surface deformation field of the earthquake,which showed that the earthquake caused complex ruptures of multiple faults and various types.Using the dislocation model of the elastic half-space,we determined the focal parameters and slip distribution on the fault plane of this event.The results reveal that:(1)the seismogenic fault of this event is an unknown fault on the northeastern edge of the Katawaz microblock;(2)The slip on the fault plane is mainly in the range of 0—8 km along the dip,with maximum slips about 2 m at a depth of 2 km,which projected on the surface is 69.44°E,32.96°N.This event suggests that,similar to the Chaman,Ghazaband and other large faults,the faults inside the microblock also play an important role in adjusting for the collision stress between India and Europe.
基金This work was supported by National Key R&D Program of China(No.2018YFC1503400)China Earthquake Science Experiment Project,CEA(Nos.2018CSES0101,2018CSES0102,and 2019CSES0107)+2 种基金Hong Kong Research Grant Council Grants(Nos.14306418,and 14304820)NSFC/RGC Joint Scheme(N_CUHK430/16)Faculty of Science at CUHK.The authors thank Dr.Pengcheng Zhou and Miss Xiang Chen for help produce the figures.
文摘Depths of earthquake occurrence and large slip distribution are critical for seismic hazard assessment.Numerous examples show that earthquakes with similar magnitudes,however,can result in significantly different ground shaking and damage.One of the critical factors is that whether the large slip was generated near the ground surface.In this article,we reviewed two aspects that are important on this regard,shallow slip deficit and nucleation depth.Understanding how shallow future earthquakes may nucleate in particular regions,such as shale gas fields,is critical for hazard assessment.Whether or not a strong earthquake may slip significantly at shallow depths(less than 3 km)plays crucial rules in seismic hazard preparation and should be further investigated by integrating high-resolution fault zone observations,dynamic rupture simulation,and fault zone properties.Moreover,precisely resolving shallow depth and slip distribution of earthquakes demands InSAR and/or other image data that can better capture the near-fault deformation to constrain the source parameters of earthquakes.
基金supported by the National Natural Science Foundation of China(10872198,50509022)
文摘A slip-line field solution is presented for the ultimate bearing capacity of the pipeline on a purely-cohesive clay soil, taking into account the circular configuration of the pipe, the pipe embedment, and the pipe-soil interfacial cohesion. The derived bearing capacity factors for a smooth rigid pipe limit to those for the conventional rectangular strip footing while the pipe embedment approaches zero. Parametric studies indicate that, the pipe-soil interfacial properties have much influence on the bearing capacity for the pipe foundation on clayedy soils.
