Research On Optimization Of Prefabricated Recyclable Double-row Pile Supporting Structure

In foundation pit support engineering,various support structures play different roles,and the double-row pile support structure is more and more widely used in construction due to its unique characteristics.The traditional double-row pile foundation pit supporting structure appeared in the late 1980s.Compared with other supporting structure forms,the research time is not too long.There is no complete calculation standard for measuring double-row piles at home and abroad to measure the supporting performance of the double-row pile supporting structure.However,with the continuous development of society and the continuous expansion of above-ground buildings,the demand for related support work in foundation pit engineering has become more urgent and more stringent.The double-row pile supporting structure has the characteristics of high supporting strength and strong resistance to deformation,and there is no need to set up counter braces and corner braces inside the foundation pit.It is widely used for foundation pit support engineering at various depths.In this paper,the traditional double-row pile supporting structure is optimized,the material of the supporting system is updated with the steel structure,the supporting piles,connecting beams and crown beams are replaced,and the piles are set between the piles and the piles.The steel structure supporting panels are used to connect at a certain distance to form a new type of assembly-type recyclable double-row pile supporting system,which solves the shortcomings of traditional materials cannot be reused and cannot be assembled.In order to understand the relevant performance of the new fabricated recyclable double-row pile supporting structure system,this paper has carried out research from different perspectives such as theoretical exploration,numerical simulation and model testing.The main research results are as follows:(1)During the excavation process of the foundation pit,the new type of double-row pile supporting pile body has a certain increase in the deformation of the pile body with the increase of the excavation depth of the foundation pit,but the overall change is not too big.After the excavation depth of the foundation pit reaches 10m,the maximum deformation of the front and rear piles appears around 10mm and the deformation of the supporting panel is also within a controllable range.Comparing the research results,it is suggested that the supporting panel should be designed with a variable thickness section in actual construction,which can better control the deformation and save the cost.(2)The loading process of the foundation pit proves that the deformation of the supporting pile is not greatly affected when the foundation pit is loaded.After the loading around the foundation pit,the maximum deformation of the front row piles and the rear row piles is 12mm,and the deformation trend of the piles has not changed.(3)Carried out a new type of double-row pile supporting structure model test,using distributed optical fiber and other instruments to measure the deformation of the supporting structure,verifying the change trend of the pile body in the numerical simulation,and the change rule of the supporting structure is further analyzed by comparing the simulation calculation results with the model test results.