Study On Side Resistance Test With Drilling With Cased Of Pipe Pile

With the drill and pipe pile as a new type of pile foundation,because it does not need mud wall protection work in the construction process,and the pile side is filled with slurry,which makes the pile side resistance accounted for a large proportion of carrying capacity.At present,there is less research on side resistance with drill and pipe pile,and it is necessary to carry out relevant experimental research.In this paper,the mechanism of the side resistance with the drill and pipe pile and its bearing characteristics,through the indoor scale model test,the field prototype test and the combination of three-dimensional scanning technology,the following aspects of research:1.For the pile side after-injection technology to improve the i MPact mechanism of pile side resistance,through the model test analysis of different post-injection types and the main factors of the main factors affecting the side of pile resistance,the main factors affecting the side of the pile resistance,respectively,The strength conditions of the pile soil interface(sticky ness,roughness),the material characteristics of the pile and soil layer.2.From the thickness of the slurry body,slurry body-soil roughness,slurry water-grey ratio,pile side different soil body and other four aspects,through indoor model test means,the study with the drill and pipe pile side slurry body-soil body shear destruction of the key factors,proved with the drill and pipe tube shear destruction The pile side shear damage surface is the slurry body-earth body collacogization surface,and it is found that the appropriate increase with the drill and pipe pile side slurp liquid water-grey ratio can effectively improve the single pile bearing performance;The pile side mo resistance is increasing.3.Using 3D laser scanning technology,the contact interface of the slurry-soil body for three-dimensional reconstruction and roughness analysis,proved that the 3D scanning technology can effectively reduce the roughness of the slurry interface,using parameters Ra and Rz on the pile side slurry interface for roughness evaluation,in which Ra and Rz values,will be with the slurry-earth body interface roughness increaseand and become larger.In addition,the indoor model test results show that: with the drill and pipe pile pile load reached a certain degree(40% of the carrying capacity),the roughness of the pile side slurry-soil interface can effectively inhibit the pile subsidence,there is an optimal threshold to match the nature of the soil engineering,the valve valve The value size increases with the strength of the soil body,in the pile side slurry body-earth body interface roughness threshold,the pile side resistance with the roughness rapidly increased,but after reaching the roughness threshold,the interface viscosity will no longer increase and gradually approach the soil body itself,The pile side resistance is now at its maximum.4,Through the two field prototype test pile of high strain test and static load test results,combined with model test data,found that with the drill and pipe pile in the vertical load action,the pile body first compressed,the pipe pile and the slurry body then produce a relative slip,the pile side is subjected to the upward resistance of the slurry body,the pile top load thus through the pile side mo resistance pile to the weekly injection and soil depth compression and deformation.With the increase of the top load of the pile,the pile body compression and pilesoil relative displacement increase,the side mo resistance in the lower part of the pile body gradually increases,the deformation produced by this process is mainly the shear deformation of the pile side slurry body and the soil body,with the continuation of the load increase,the pile side mo resistance will be fully played.