Influencing Factors And Risk Analysis Of Modern Ground Fissures In Hengshui City

Since the 1980 s,ground fissures have frequently occurred in Hengshui City,where the ground fissures have passed has caused a large number of property losses.The ground fissure disaster is irresistible.Therefore,it is of great significance to analyze and evaluate the vulnerability of ground fissure in a region for the prevention and control of ground fissure disaster and the normal operation of Engineering construction.In this paper,the related data of ground fissure development in Hengshui city in recent years are collected extensively,and the development and distribution law of ground fissure in Hengshui city are summarized.The most densely distributed areas of ground fissures in Hengshui City are located in Anping County,Raoyang County and the northern part of Shenzhou City.From the distribution location,the ground fissures in northern Hengshui are characterized by active faults.From the time of formation,the ground fissures in Hengshui city are accelerated with the massive exploitation of groundwater.In order to quantitatively evaluate the influence of these factors on ground fissures,this paper selects six factors which have great influence on the development of ground fissures,and calculates the correlation degree between these factors and ground fissures by using grey relational degree method.The order of correlation degree from large to small is: deep groundwater depth > shallow groundwater depth > Quaternary sedimentary thickness > land subsidence > distance from Quaternary active fault > topography and landform.The correlation sequence shows that groundwater is the most important factor affecting ground fissures,and the exploitation of groundwater accelerates the development of ground fissures.The occurrence of ground fissure is both inevitable and accidental.The inevitability lies in that under certain geological conditions and external forces,the soil will reach the stress limit and produce rupture.The contingency is that the occurrence of ground fissures is affected by many factors,and the influence of these factors on ground fissures and their relationship is complex,which makes it difficult to predict the specific location of soil fracture.In this paper,MAPGIS spatial analysis technique is used to predict the locations of ground fissure easily.Firstly,according to the above ranking,combined with the method of constructing two-to-two comparison judgment matrix in AHP,the weight distribution of six influencing factors is carried out.Afterwards,the selected six factors are stored in six layers,and then six layers are superimposed in space.Finally,the overlapped layer attributes are weighted and synthesized to get the evaluation score of vulnerability.According to the results of MAPGIS zoning,Anping County,Raoyang County,northern Shenzhou City and central and southeastern Hengshui City in the north of Hengshui City are vulnerable to ground fissure disasters,which is basically consistent with the actual situation.However,the results of MAPGIS zoning show that the development of ground fissures is not very serious in some fractured areas and more dangerous areas,mainly because the current geological environment is prone to produce ground fissures,but the inducing factors are less,so in these areas to reduce the damage of human activities to the geological environment,to prevent ground fissures.Produce.