| As a special underground hole structure,Kanerjing is widely distributed in arid desert areas.With the rapid development of modern social transportation and the development strategy of China’s high-speed rail "going out",a large number of high-speed railway lines will cross the Karez area,which may cause a series of geological engineering problems of the Karez subgrade,which seriously affects the construction of the high-speed railway project and Operation.However,at present,there is little engineering experience on high-speed railways or highways crossing the Karez area,and there is a lack of research on the engineering geological characteristics of the Karez foundation and the physical and mechanical properties of the Kaner foundation soil within the high-speed railway.The construction of railways in the region is full of many potential dangers.In response to the above problems,this paper relies on the Iranian Tehran-Kum-Isfahan high-speed railway project,through field investigation,field test,indoor test,statistical analysis of test data and numerical simulation to carry out research,design and construction of high-speed railway crossing Karez area with engineering practice significance.The following results have been achieved through systematic research:(1)Using geophysical prospecting,drilling,pipeline robot and cone dynamic penetration test,etc.,the location,depth and relationship between the Kaner well along the line were ascertained,and the high-speed railway project in Karez area was summarized and studied.(2)According to the geological survey data and in-situ test data of the line range,combined with typical work points,the particle composition,gradation range and foundation of the foundation soil were studied through particle test,direct shear test,compression test and triaxial test.The physical and mechanical properties of soil.A series of static triaxial tests under different drainage conditions were carried out using standard sand as raw materials.The mechanical properties of sandy foundations in Karez area were further studied,and the stressstrain relationship of sand under different shear conditions was analyzed.(3)Based on the obtained test data,the physical and mechanical parameters of the soil along the line are statistically analyzed to study its parameter variability;the probability distribution characteristics are analyzed using the probability density estimation method,and the random distribution test is carried out.The analysis results can provide a basis for the selection of random finite element and reliability analysis parameters of the same type of soil.(4)According to the upper and lower theorems,combined with the finite element method,based on the non-linear Mohr-Coulomb failure criterion,the ultimate bearing capacity and failure mode of the Kaner well foundation under different conditions were studied,and the buried depth.The influence of soil strength parameters c,φ value and underdrain radius on the ultimate bearing capacity and failure mode of Karez foundation. |
