Experimental Study On Interface Friction Characteristics Between Pile And Soil

The pile is an important foundation form, and it is extensively used in railways,roads, bridges, ports and high-rise buildings. Interface friction between pile and soilhas much influence on the strength and distortion of the ground base and the upperstructure, so it is a key concern in pile foundation design, and it is an importantmechanics to study the side friction which determined the holding capacity andsettlement of the pile foundation. Although many researchers have done a lot of work,most of which focus on clay and sand, researches about silt are much less. Facing theproject like CHENGDAO silt ground base of SHENGLI oil field, there is almost nocriterions to be base on, and which leads many deficiencies to designs, constructions,detections and safeties of the project. Under these conditions, aiming to fill up thedeficiency and blank of the interaction between pile and silt, a serious of model testsare carried out.The model tests of interface friction between pile and soil can be divided intodirect shear tests and pullout tests. They are not of big difference between the testmethods, but according to the analysis of the test instruments, the box of direct sheartest exist some deficiencies by being compared to the box of pullout test. So it isbetter to choose the pullout test for studying the interface friction between pile andsoil in a sense. Based on the improved box of the pullout test, this article employs thepullout method to study the interface friction between steel plate and soil, whichinduce the interface friction between steel pile and soil.The mechanics of interface friction between pile and soil is very complex, as itis not only related to the engineering properties of soil, but also it is related to theengineering properties of the pile. The moisture content, drawing speed and verticalpresser have some influences on the interface friction between pile and soilaccording to test results, and the drawing speed has only small influences while themoisture content and vertical pressure have significant influence. Based on themechanics of static soil, the distribution cure of the ultimate side friction resistancealong the pile depth is deduced, which is useful for the study of holding capacity andsettlement of pile foundations.