In-situ Test Method of Radial Extrusion Earth Pressure in Borehole for Geotechnical Investigation
Since the introduction of squeezed branch pile in the late 1980s,it has played an important role in improving the bearing capacity of pile foundation,reducing settlement,improving the safety of pile foundation and reducing project cost.The extrusion pressure value is the key index to determine the number,position and spacing of the squeezed branch,which directly determines the bearing capacity of the squeezed branch pile foundation.At present,the squeezing pressure value is collected in real time during the construction of squeezed branch pile,which cannot be obtained in the design stage.In this paper,it is proposed to carry out the miniaturization transformation of the extruder,which can be put into the borehole to carry out the extrusion operation,and obtain the extrusion pressure value through the inner side of the borehole to the soil.It can not only be used for the design of the squeezed branch pile,but also analyze and study the mechanical indexes such as the bearing capacity of the rock and soil layer.As a new type of in-situ test method for conventional geotechnical engineering investigation,the research is of great significance and has broad application prospects.
squeezed branch pileextruderextrusion pressure valuedrillingin-situ test