Exploration Of Foundation Treatment Methods For Covered Karst Foundations

The lava landform is the floorboard of the surface and underground forms formed by the dissolution of water on soluble rocks(mostly limestone).In addition to the corrosion,it also includes the erosion of the water,the erosion,and the mechanical erosion process such as collapse.The harm of the karst landform in engineering construction,especially the existence of covered karst,often unable to accurately estimated its existence,location,size,shape and other properties,lacking in the process of engineering construction,vulnerable to all kinds of accidents.The karst form in shenzhen is mainly distributed in the longgang district,pingshan new area and dapeng new area,and most of them are covered in karst.Due to karst region of hydrological characteristics and unique topographical features,surface formation ups and downs,so in karst region for production of various kinds of economic construction and life will have no problems-in karst region,not easy to cause the geological disasters such as collapse,landslide and debris flow.In karst region,due to the presence of large amounts of subterranean cavitation,project construction,leakage problem,attention should be paid to prevent collapse in tunnel and other underground construction,when should pay attention to water drainage problem,should pay attention to when building the subway,railway,bridge foundation subsidence problems.Through the brief introduction of the formation,mechanism and hazards of covered type karst,two examples of engineering construction of typical covered type karst area in Shenzhen are selected in the author's work.First,in terms of karst geological prospecting,the shenzhen covered karst buried depth is deeper,high-rise building with pile foundation in karst area,introduces the high density resistivity method is used to find out the method of subsoil karst geological character of pile foundation;Secondly,this paper introduces the technology of detection of pile foundation bearing stratum by geophysical exploration in karst area.Third,in the pile foundation construction,the paper introduces the technology of using the jet grouting pile to treat karst cave before the construction of rock-socketed pile;finally,the paper introduces the method of using LC pile composite foundation in karst area.Through the analysis of investigation,design and subsequent construction,this paper discusses the feasible scheme of engineering construction in karst area of Shenzhen covered type,and provides the key technical reference for the construction of similar karst area in Shenzhen in the future.