Study On Construction Technology And Bearing Capacity Of Bored Piles In Karst Area

Pile foundation is one of the basic forms of high-rise buildings in our country.The single pile of rotary-boring cast-in-place bored pile has the advantages of high bearing capacity,small settlement and short construction period.It is widely used in various high-rise buildings to overcome the insufficient bearing capacity of foundation.However,due to the existence of karst and other unfavorable geologic functions,the borehole cast-in-place piles in karst areas have many problems in surveying,designing,and construction.In order to ensure the capacity and stability of rotary-bored cast-in-place bored piles at the late stage of construction can meet the requirements,it is of great theoretical significance and practical value to carry out research on the bearing capacity of rotary bored cast-in?In this paper,the main rules of karst cave development in karst area are introduced,and the influencing factors and bearing mechanism of the rotary boring and cast-in-place piles in this area are analyzed.Combined with previous research and analysis and related literature,the calculation method for bearing capacity of karst areas in Guilin was obtained.The size and shape of the underlying cave or soil cave,the presence of groundwater and the height of the water level,the composition of the foundation soil,and the filling in the cave are all factors that affect the bearing capacity of the karst foundation.Careful consideration must be given to these factors.Analysis can only lead to the most reliable and reliable solution.The geology in the karst area is extremely complicated,and it also poses great challenges to the construction of the pile foundation.Therefore,the paper discusses the construction technology of the pile foundation in detail.During the process of construction of bored cast-in-place bored piles,problems such as eccentric holes,slanted holes,and leakage of pulp are likely to occur.The solutions to these problems are also described.In addition,through the static load test and FLAC3 D numerical simulation analysis,the mechanical characteristics and bearing mechanism of bored cast-in-place bored piles are studied.After simulating the piles,the piles are loaded 1-9 levels after the completion of the construction.The results obtained by numerical simulation are in good agreement with the field static load test,indicating that FLAC3 D numerical simulation software can simulate the force state of the pile better.Finally,the effect of the hole on the pile body is simulated with FLAC3 D numerical simulation software.It is assumed that the effect of the karst cave on the stability of the foundation will be simulated when there is a karst hole at the bottom of the pile,0 meters,1 meter and 2 meters.Some conclusions are drawn from the analysis of the stress cloud diagram of the pile at the base of the FLAC3 D numerical simulation,which provides reference for the design and construction of pile foundation in karst area.