| With the construction of more and more kinds of projects in recent years,it is inevitable to choose to build projects in karst areas,and all kinds of adverse geological problems are accompanied.As an economical and effective method,CFG pile composite foundation technology plays an increasingly important role in foundation treatment.However,the application of CFG pile composite foundation treatment in karst areas is still very lacking in the stability evaluation of karst site application.In addition,there are some deficiencies in the bearing capacity and settlement deformation,especially in the theoretical study of settlement deformation.Based on the Literature Review and the actual engineering case in Guilin area,the present research situation of CFG Pile Composite Foundation and the study of foundation stability and the actual situation of adverse geological action in Guilin Karst area are analyzed and summarized in detail on the basis of the original geological data and theory,the calculation method of bearing capacity and settlement deformation of CFG pile composite foundation is discussed.In this regard,some achievements have been obtained,which provide some reference value for similar projects in the future.(1)The calculation methods of three kinds of bearing capacity of CFG pile composite foundation are analyzed and summarized.(2)Two typical settlement calculation methods are analyzed and a modified formula is presented.(3)In this paper,the influence of the stability factors on the stability of the overlying karst face and the roof of the karst cave under the pile end is summarized.The evaluation method of the stability of the overlying karst face is summarized from qualitative to quantitative,and the evaluation method of the roof stability of karst cave is summarized from qualitative to semiquantitative to quantitative process.(4)The stability of karst ground treated by composite foundation of pile foundation and CFG pile is analyzed and discussed(5)Combined with the practical engineering case,considering the practicability and conciseness of the three calculation methods of bearing capacity,the code method is recommended to calculate the bearing capacity of Composite Foundation.Through the comparison and analysis of the measured value of settlement amount in static load test and the theoretical calculation value,the calculation result of the modified formula is superior to the standard method,which verifies the feasibility of the modified formula and can be used in engineering practice.(6)The comparison between CFG pile composite foundation and pile foundation shows that when CFG pile composite foundation technology is used to treat karst foundation,not only the bearing capacity and settlement deformation can better meet the design requirements,the use of restriking measures also ensures stability.At the same time,it highlights the superiority in technology and economy. |
