Physical Model Test On Influencing Factors And Subsistence Process Of Typical Strata In Cangzhou

With the rapid development of China’s economy and the continuous expansion of urban construction,building load has become a non-negligible factor causing land subsidence.It is of great significance for land subsidence prevention and control to discuss the relationship between building load,groundwater exploitation and land subsidence,and further clarify the influencing factors of land subsidence.Based on the research background of land subsidence in Cangzhou area,this paper carried out physical model test and related numerical simulation on the influence of groundwater exploitation and building load on land subsidence,and analyzed the evolution law of subsidence.The main conclusions are as follows:The physical model test shows that the settlement under the combined action of pumping and load is significantly greater than that under the single action of pumping.The maximum loading of the physical model simulates a 34-story house.The settlement range can be extended to 1.5 to 3 times the width of the foundation in the horizontal direction,and the depth can reach 75 m.Land subsidence rate is positively correlated with drainage rate.Groundwater recharge has a certain effect on the settlement recovery of silt and sand strata.Comparing the physical test results with the monitoring data of land subsidence in Cangzhou City:the similarity between the two is high,indicating that the model test results can reflect the actual situation of land subsidence in Cangzhou City to a certain extent.The numerical simulation results show that under the combined action of load and pumping,the settlement in the initial stage is mainly caused by building load,and the subsequent settlement is mainly caused by pumping.At the same time,the settlement slows down and the compression difference of each soil layer becomes smaller.The continuous exploitation of deep groundwater will make the uneven settlement of shallow soil layer caused by building load smaller.Finally,only the local settlement of the loading range is uneven,and the rest of the settlement is basically uniform.