Research On The Parameters And Bearing Characteristics Of Main Rock And Soil Layers In Xinyu City

The parameters of rock and soil layer are important indexes that affect the bearing capacity of rock and soil layer.It is very important to correctly use the parameters of rock and soil layer to reasonably select the type of foundation,not only to ensure that the deformation of the proposed building is within the scope of the code,but also to avoid excessively high construction cost caused by conservative design.In this paper,the geotechnical mechanical parameters of several representative projects in Xinyu city district are statistically studied,and the relationship between the pore ratio and compression coefficient,plastic index and liquid limit,cohesive force,internal friction Angle and water content of silty clay is analyzed.The results of load test of shallow plate are compared with the standard value of bearing capacity provided in geological survey report.Based on the analysis and study of the static load test data of the foundation pile with defects in the pile bottom bearing layer of several projects,the estimation value of the limit lateral resistance coefficient of the manually dug hole pile in Xinyu city was put forward.The main work and research results of this paper are as follows:1.in this paper,at regional geological condition has carried on the brief description,introduced at the location and the main geological characteristics,and the specific project at urban areas were summarized,the soil layer distribution is analyzed in detail,through field survey and geotechnical test,record and statistical parameters of the typical silty clay at area a total of more than 550 groups of experimental data,obtained the characteristic statistic.Through statistical analysis,the distribution histogram of each silty clay parameter is drawn,which can reflect the specific distribution of silty clay directly.Furthermore,the distribution type hypothesis of each silty clay parameter was proposed and verified.The results show that the probability distribution types of each parameter all meet the classical probability distribution types such as normal distribution and lognormal distribution.This result provides a specific reference for the geotechnical investigation in Xinyu Urban area,so as to grasp the geotechnical distribution in this area in advance.2.By making full use of the parameters of silty clay obtained from field experiments and laboratory tests of various projects in Xinyu urban area,the linear regression analysis is carried out for each geotechnical parameter,and the linear regression equation is established for the strongly correlated parameter combination,which can be used as an empirical formula for the preliminary study of the parameters of silty clay in this area.The relationship between the standard penetration number and compressive strength of silty clay and the bearing capacity of foundation in Xinyu city is analyzed,and the corresponding formula is established,and the general formula of the bearing capacity of foundation in Xinyu city is obtained,which can provide some help for the engineering investigation and design in this area.3.Based on the rock-base load plate test,it is concluded that the bearing capacity characteristic value of the weathered pelitic siltstone in this project is generally greater than 2000 k Pa,which is more than twice the characteristic value provided by the geological survey report,indicating that the bearing capacity characteristic value of the weathered pelitic siltstone provided by the current geological survey report is too conservative.4.It is found that the characteristic value of the bearing capacity of the silty clay foundation measured by the load test is more than 25% higher than that put forward in the geological survey report after the load test of the silty clay shallow plate.5.When the manual digging pile bottom holding layer is very soft(when the drilling core detects the pile bottom holding layer,the penetration will be very fast and the drilling will be lost),the limit side resistance coefficient can be used to estimate the ultimate bearing capacity of the defective pile,which provides reference for the design department to conduct reinforcement treatment.