| Foundation size determination is an important phase of foundation design,the relationship of foundation size and foundation settlement in different soil layer needs to be definitude,In this thesis,a mass of investigations have been conducted aim at this problem.Firstly introduces the present state of studying the relationship between settlement in loess foundation soil and foundation size,it is found that ABAQUS has great predominance in Geotechnical Engineering calculation.Property parameters of loess were obtained from literatures.Based on these property parameters,choose appropriate model size and yield criterion,and analyzed by using ABAQU.First As an example of homogeneous,studies on basic dimensional effect on loess foundation settlement under strip load,the foundation settlement under uniform loading is nonlinearly increased along with the increase of strip foundation size.However,as the increase in foundation width,the settlement is gradually reduced,and it is gradually convergence,ratio of settlement is independent of property parameters,in direct proportion to the relationship with the ratio of load。Based on the calculation of double layer loess foundation which is formed by hard overlying and soft underlying layers under uniform load,obtained that foundation settlement of this kind of foundation is nonlinearly increased along with the increase of foundation size under uniform load,the differences in settlement which caused by the change of overlying thickness under uniform loading and same foundation size is smaller when the foundation size is smaller,and the settlement caused by the increment of foundation width is also smaller when the foundation size is much larger.At last through simulate the situation that top load invariableness to put up calculation,obtain the conclusion that the foundation settlement of double layer loess foundation which is formed by hard overlying and soft underlying layers is nonlinearly decreased along with the increase of foundation size under invariableness centralized strip load and gradually convergence.The difference in settlement which caused by the change of overlying thickness in double layer foundation under same foundation size is much larger when foundation size is smaller,and the settlement is more sensitivity when the foundation size is much more smaller.Though contrast data discover when foundation size reach to a certainty degree,its influence to groundsill settlement is very small,Though to the small foundation,increase its size in order to reduce the settlement is effective,but to the large foundation,is inadvisable to use the method. |
