Research On Settlement Deformation Analysis Method Of Loess Foundation Based On The Chord Modulus

As the rapid development of engineering construction in loess area, the stability and deformation of loess is becoming the focus in loess foundation projects.So it is needed to determined the reasonable bearing capacity and analysis settlement of foundation in actual project.Typically, the foundation bearing capacity is determined by limit equilibrium theory and in-situ load testing based on its nature of projects.And the foundation settlement is calculated by soil compression modulus, using layer dividing summation method. But there exists some error in bearing capacity determined according table and theoretical analysis, and the load test is of large cost. The layer wise summation method to calculate the foundation settlement is based on compression modulus that is obtained from confined deformation and attached stress, which is different from the actual condition, and a coefficient is needed to amendment the calculated settlement. Therefore improving the method to determine and analysis bearing capacity and settlement is of great importance and practical significance.This paper research loess foundation,based on lots of load tests,and analysis different the non-linear curves of additional pressure and settlement, further more research the relationship of the soil elastic modulus, chord modulus,foundation bearing capacity with soil physical and mechanical property.The acquired results are as follows:1) The relationship,which is between the foundation bearing capacity, foundation soil elastic modulus and void ratio, moisture content, liquid limit and plastic limit, liquid index, indicate that the engineering properties of foundation is directly bound up with structural stress.2) This paper comes up with a new method that divides the foundation soil under the plate into three layers and determined the chord modulus by the increment of additional stress. And build up soil chord modulus table classified by different void ratio, water content, liquid limit and additional stress of soil.3) Apply the relationship of the loess structure and compression modulus to the chord modulus, and determine the structure stress of 58 load test, thereby establishing the chord modulus table classified by the structure stress and void ratio.4) According to the new chord modulus table,this paper predicts the curves of pressure on the plate and corresponding settlement,which gives a new way to consider the loess structure,so as to reasonably determine the foundation bearing capacity.Loess, distributing in Western China,is a special type of soil with typical structural stress. Enriching and deepening the chord modulus table will be of broad application in loess foundation engineering projects.