Study On The Deformation Characteristics And Construction Technology Of Foamed Lightweight Soil Subgrade

With the rapid development of China's infrastructure construction,the soft soil foundation expressway is being built in great quantities.However,it has been a technical problem for engineers to build soft soil roadbed for long time,large settlement deformation,long settlement deformation and uneven distribution of roadbed.In this paper,the guangfo fast-track jiangmen jiang period of test road as the backing,from the perspective of changing traditional thought,using new lightweight materials-foamed light-weight soil,by increasing bearing capacity of soft foundation under subgrade or degree of consolidation to reduce roadbed dead load and improve the idea of foundation consolidation ratio,the field test and finite element numerical simulation method of combining the,of foamed light-weight soil subgrade base stress,strain,and the surface subsidence,deep soil settlement are analyzed,such as the main research contents and results are as follows:(1)Based on the jiangmen section test road of guangfujiang expressway,the flow value,unconfined compressive strength and wet weight of foamed light-weight soil under different water and solid conditions were studied and analyzed.It is obtained by field test,flow value of the foamed light-weight soil increases gradually with the increase of the ratio of water and solid,the unconfined compressive strength,wet severe decreases gradually with the increase of water solid ratio.(2)Through the analysis of field measured data of foundation stress,the change of the base stress has a great influence on the change of height.The time of the base stress in the interstitial hardening stress during the clearance period is shorter than that of the new 6m foamed light-weight soil subgrade.(3)Compared with the conventional filling,foamed light-weight soil in load drop-off is low,under the same filling height,foamed light-weight soil subgrade settlement also is only half of ordinary fill subgrade;The subgrade subsidence of subgrade subsoil is similar to the inverted trapezoid distribution under the rigid load,and the foam light soil is more effective for the uneven settlement of the subgrade.(4)With the increase of the filling height of foamed light-weight soil subgrade,the settlement of subsoil decreases gradually,but when the change of filling height reaches a certain value,the increase of the base settlement is almost constant with the increase of the filling height.(5)By establishing the corresponding solid model and using the finite element software,the foamed lightweight soil subgrade under different structural forms was studied.The simulation results were analyzed and found that,in different structural forms,the foamed lightweight soil subgrade,the maximum settlement of the basement and the maximum stress value are basically the same,but the distribution of the base stress and the settlement distribution are not the same.In the treatment of uneven settlement,the foamed light-weight soil + the mixed embankment and the vertical embankment should be better than the foamed light-weight soil embankment in the form of trapezoidal structure.The above research results have been successfully applied to jiangmen section of guangfu river expressway,which has good reference significance for the construction of other soft foundation roads.