Research On Load Collapsibility Of Loess-like Soil In Harbin And Incline Analysis Of Qilu Building

The engineering geological conditions in Harbin are good,but there are loesslike soils with a certain thickness distributed in different geomorphic units.The loess-like soils have certain collapsibility.Especially when they are subjected to large loads and encounter water,obvious collapsibility deformation will occur,resulting in cracks,inclination and even destruction of buildings.Since the collapsibility coefficient of loess-like soils does not meet the criteria of collapsible loess,they are often described as cohesive soils in the geological investigation reports.They have caused engineering accidents because engineering designers fail to consider the existence of loess-like soil,so designers should pay full attention to loess-like soil.In this context,the following work has been done in this thesis:1.Based on the test data of loess-like soils samplings in Harbin urban area(samplings of Harbin University of Technology,Campus Ⅱ),the uniaxial compression tests of loess-like soil with different moisture content were carried out by humidifying and dehumidifying the samples,and the influencing factors were analyzed.The collapsible deformation law of loess-like soil in Harbin area is reflected by a large number of experiments.2.A method for calculating collapsible compressive modulus of loess-like soils in Harbin area is proposed.According to a large number of experimental data,a comprehensive analysis of Harbin loess soil is carried out,and the test error of two-line method and single-line method is compared.The factors affecting collapsibility and the mechanism of collapsibility are discussed.The characteristics of collapsible deformation of loess-like soil in Harbin area are compared and tested.The data was analyzed in detail,and the reference value of the compression modulus of loess-like soil in Harbin was proposed.3.Finally,the reasonability of the compressibility modulus was verified by the slope accident analysis of Harbin Qilu Building.The “point source” threedimensional infiltration model is established according to the infiltration law of groundwater.The ABAQUS software is used to calculate the displacement of the top floor of building caused by collapsibility of loess-like soils.The results are close to the actual monitoring results,which further verifies that the compressibility modulus has a certain application value and can provide reference for other damp loess-like buildings.