| Green sustainability is one of the main directions of the cities' development in the future.One of the measures is using the construction trash which is caused from cities' buildings to make piled mountains in China.High-stress and large-area engineering loading puts high demands on the foundation.Many similar projects have problems or even engineering disasters are caused by improper foundation design.At the same time,this type of project does not have the characteristics of simple filling and uniform force such as high-filled roadbed and shape-consistent building entities,and the design range is limited in the dense environment of urban complex structures.Therefore,it is of great significance to study how to rationally arrange,optimize the foundation treatment scheme and explore the foundation settlement deformation characteristics under multilevel stress loading conditions to avoid and eliminate the adverse consequences caused by differential settlement.Combined with the Bai Wang piled mountain project in Xingtai City,Hebei Province,the effects of the project on the surrounding buildings and the environment were revealed through numerical simulation,field test effect detection and deformation characteristics of the foundation.The design of the foundation treatment of the project was optimized and carried out.Finally,combined with laboratory experiments,the calculation formula of foundation settlement under the influence of complex stress loading history is proposed.It provides a reference and theoretical basis for the scientific and rational design of foundation reinforcement methods and settlement prediction for such projects.The following are the main contents and research results of this article:(1)Through the 3D/2D modeling finite element analysis,the numerical effects of the height effect of the mountain and the impact on surrounding buildings and environment are numerically simulated.The results show that there is a phenomenon of "mutation,transition" in the height effect.When the stacking height is greater than 42 m,the influence of the mountain body on the displacement stress of the surrounding environment suddenly increases.The whole project has obvious partitioning behavior on the stress displacement of the foundation.Adopting corresponding ground treatment methods for different stress zones can effectively reduce the economic cost of ground treatment and eliminate the differential settlement caused by the foundation.(2)The field test results including the excess pore water pressure and foundation strength were tested on the optimized ground treatment plan.The test results show that the improved ground treatment method can effectively accelerate the dissipation of pore water pressure in the soil under high stress level.The dissipation degree reaches 90% and only takes about 2 hours.The improvement of foundation bearing capacity is more than 1.8 times,which fully meets the strength requirements of the pre-project.(3)Combined with the indoor test,the calculation formula of foundation settlement prediction for high-loading mountain engineering is proposed,and the data of the compressive modulus of soil under different stress levels is fitted,and based on the Janbu formula,it is deduced according to different The soil properties have been adjusted accordingly.After comparison,the fitting effect was found to be good.Finally,the method of predicting the settlement of the main consolidation settlement of this kind of stacking project is put forward.After comparison with the measured data,the effect is better. |
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