Study On The Settlement Law Of The High Fill Foundation In The Gully Area Of Collapsible Loess

In this paper,based on the engineering example of the high fill foundation in the collapsible loess area,the settlement law of the high fill foundation in the collapsible loess area was explored by the method of indoor geotechnical test and numerical simulation,and some influencing factors of the settlement were discussed and analyzed,which provides some new ideas for the construction and design of the similar high fill foundation in the collapsible loess area.The main contents of this paper are as follows:The joint test of liquid plastic limit,light compaction test,particle analysis test by densimeter,consolidation test and three axis test was carried out with the soil sample at the site foundation.The basic physical and mechanical properties of collapsible loess in this area were measured,and the material parameters needed for subsequent analysis were obtained.By using ABAQUS finite element software to simulate the settlement,horizontal displacement and stress of the high fill foundation,the preliminary analysis of the settlement law of the high fill foundation was obtained,and the result is also in line with the analysis of the traditional geotechnical engineering.Using ABAQUS software,this paper analyzed the settlement law of the high fill foundation in the gully from six aspects: topography,slope angle,water influence,filling height,contrast of compression modulus between the filling body and the original foundation,and excavation of steps.In the aspect of topography,the difference between the high fill foundation of gully and the high fill foundation of horizontal ground was compared.In the aspect of gully slope angle,the models of different slope angles were established for comparative analysis.It is found that when the slope angle is 45 °,the settlement of gully high fill foundation is the smallest.In the aspect of water effect,by changing the three parameters of compression modulus,cohesion and internal friction angle in the numerical simulation to compare their effects on the water effect of the high fill foundation,it is found that the change of compression modulus has the greatest impact on the settlement of the high fill foundation.In the aspect of filling height,the change of settlement law of high fill foundation with the increase of filling height in the same gully terrain was analyzed.Comparing the compression modulus of the filling body with that of the original foundation,it was found that the compression modulus of the original foundation has a greater impact on the high gully filling foundation.After analysis,it was found that the construction method of excavating steps can effectively reduce the settlement of the high fill foundation.