Identification of Marker Layer and Determination Depth of Bore Hole in Xi’an Ground Fissure Second Class Site

Xi'an ground fissure is a kind of regional geological disaster.At present,14 ground fissures have been found in Xi'an,which bring different degrees of harm to Xi'an's engineering construction.Usually,the Upper Pleistocene and Middle Pleistocene reddish brown palaeosol are used as exploration marks during investigation in the second class of Xi'an ground fissures site.According to the characteristics of Xi'an topography and stratigraphy,the second class of Xi'an fissures site can be classified into 3 sub regions.It is suggested that we should use the corresponding judgement of the outburst signs and exploration depth in different sub regions.It has guiding significance for the layout and process implementation of second class of Xi'an ground fissure sites.