Nearly 1100 fissures have formed on the Hebei Plain in China.Within the Yellow RiverQinghe River-Zhanghe River shallow buried paleochannel band on the plain,93 ground fissures controlled by paleochannels have develope...Nearly 1100 fissures have formed on the Hebei Plain in China.Within the Yellow RiverQinghe River-Zhanghe River shallow buried paleochannel band on the plain,93 ground fissures controlled by paleochannels have developed,of which the Wuyi-Fuping ground fissure is a typical paleochannel-controlled fissure located in Hengshui,Hebei Province,with a total length of 3 km,a dominant strike of NE78°,and nearly upright in the shallow layer.The surface damage observed in this fissure primarily manifests as beaded pits,and its activity shows distinct segmentation characteristics.On the trench profiles,the offset distance of shallow layers remains consistently around 20 cm within the depth range of 0 to-3 m.An evident flexure is observed in the strata at depths ranging from-4.5 to-7 m.The drilling profile reveals that there is an absence of dislocations in the deeper strata.Nonetheless,the shallow seismic physical profiles unveil the presence of underlying faults beneath the study area,underscoring the intricate formation process and genesis mechanism of the Wuyi-Fuping ground fissure.Firstly,the formation and evolution of the Qingling River's paleochannel were shaped by the actions of fault blocks and underlying faults.The interplay of the regional stress field,fault block movement,and fault activity played pivotal roles in driving the development of this paleochannel.Secondly,the paleochannel exerts a controlling influence on the development location and severity of the fissure.During pumping,the confined aquifer within the paleochannel undergoes water loss and compression,resulting in the formation of a surface subsidence funnel.When the tensile stress surpasses the soil's tensile strength at the funnel's edge,the soil fractures give rise to a ground fissure.Finally,large amounts of surface water generated by heavy rainfall and irrigation can cause existing hidden ground fissures to rupture,emerge,and expand.This paper provides a heretofore generally unknown example,promotes research on the mechanisms of paleochannel-cont展开更多
基金funded by the National Science Foundation of China(Nos.2022XAGG0400,42207202,42293351)the Open Fund of the Key Laboratory of Earth Fissures Geological Disaster,Ministry of Natural Resources,Geological Survey of Jiangsu Province,China(No.EFGD20240604)+2 种基金the Open Fund of the Observation and Research Station of Ground Fissure and Land Subsidence,Ministry of Natural Resources(No.GKF2024-06)the Fundamental Research Funds for the Central Universities of China University of Geosciences,Beijing(No.2-9-2021-014)the Fundamental Research Funds for the Central Universities of Chang'an University(No.300102264501-01)。
文摘Nearly 1100 fissures have formed on the Hebei Plain in China.Within the Yellow RiverQinghe River-Zhanghe River shallow buried paleochannel band on the plain,93 ground fissures controlled by paleochannels have developed,of which the Wuyi-Fuping ground fissure is a typical paleochannel-controlled fissure located in Hengshui,Hebei Province,with a total length of 3 km,a dominant strike of NE78°,and nearly upright in the shallow layer.The surface damage observed in this fissure primarily manifests as beaded pits,and its activity shows distinct segmentation characteristics.On the trench profiles,the offset distance of shallow layers remains consistently around 20 cm within the depth range of 0 to-3 m.An evident flexure is observed in the strata at depths ranging from-4.5 to-7 m.The drilling profile reveals that there is an absence of dislocations in the deeper strata.Nonetheless,the shallow seismic physical profiles unveil the presence of underlying faults beneath the study area,underscoring the intricate formation process and genesis mechanism of the Wuyi-Fuping ground fissure.Firstly,the formation and evolution of the Qingling River's paleochannel were shaped by the actions of fault blocks and underlying faults.The interplay of the regional stress field,fault block movement,and fault activity played pivotal roles in driving the development of this paleochannel.Secondly,the paleochannel exerts a controlling influence on the development location and severity of the fissure.During pumping,the confined aquifer within the paleochannel undergoes water loss and compression,resulting in the formation of a surface subsidence funnel.When the tensile stress surpasses the soil's tensile strength at the funnel's edge,the soil fractures give rise to a ground fissure.Finally,large amounts of surface water generated by heavy rainfall and irrigation can cause existing hidden ground fissures to rupture,emerge,and expand.This paper provides a heretofore generally unknown example,promotes research on the mechanisms of paleochannel-cont