Formation mechanism and development process of karst collapses in Tanluo town of Nanning City
SHI Shu-jing
ZHANG Qin-jun
KANG Zhi-qiang
Abstract：Karst collapse is a common geohazard in karst areas.Proper study on its formation mechanism may help to prevent and control those incidents.In June 2012,a cluster of karst collapses happened in Tan-luo town of Nanning City,with 1 9 collapse pits occurred in 26 days.In order to understand the formation and development mechanism of Tanluo Karst Collapse Cluster (TKCC),many works including field investi-gation,geophysical exploration,hydrogeological and engineering geological drilling,dynamic groundwater monitoring,rocks and soil sample tests were carried out.The results indicated that multiple adverse factors that had contributed to the development of the TKCC,of which the specific water-soil-rock interaction and human activities were the major ones.Groundwater is shallow in the study area.The topsoil is cohesive with low permeability and easy to collapse.The underground karst is well developed.However,the TKCC was induced by overexploitation of groundwater.Further investigation shows that the formation and occurrence of the TKCC was contributed by the coupled effect of creep seepage,increased load and water level fluctua-tion which resulted in hydraulic pressure difference.The collapse patterns are the combination of gravita-tion-,erosion-,vacuum cavitation-and burst-collapses.Based on the occurrence sequence of the karst collap-ses,it is inferred that the development process of the TKCC can be divided into three phases and each stage has its different development mechanism.The original soil balance was destroyed by different types of geo-logic forces so that the karst collapse could happen.
Keywords：karst collapseinfluence factorformation mechanismdevelopmental phasesTanluo town of Nanning city
Publication Date：2015-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：8( 507-514 )