Study On The Foundation-sluice Interaction Mechanism And Reinforcement Technology Within Subsidence Areas

Reinforcement transformation method is an efficient way to harness the sluicewithin subsidence areas; the premise is to accurately obtain the stress condition of thesluice under the influence of mining based on soil-structure interaction. Thefoundation-sluice interaction within subsidence areas is influenced by mechanicalcharacteristics of disturbed soil-structure interface. However, a systematic study of theshear behavior of this disturbed soil-structure interface is relatively limited andinfrequently reported in the literature. As the foundation-sluice interaction withinsubsidence areas is highly complex, it is insufficient to analyze the spatialstress-deformation behavior by using the plane finite element method. This papersystematically studies the foundation-sluice interaction within subsidence areas, basedon a series of3-D finite element analysis. Which is great significant to the reliabilityof the sluice within subsidence areas and availability of underground resource.Based on the variation regularity of disturbed soil in mining subsidence areas, aseries of disturbed soil-structure shear tests was performed by DRS-1direct shearexperiment system. The shear characteristic of the soil-structure interface wassystematically studied. The influences of normal stress, initial porosity ratio andinitial saturation for interface were analyzed.A series of disturbed soil-structure sheartests under the water immersion condition was performed by a newly developed shearexperiment system. Based on data comparison，the reliability of newly experimentsystem was validated. The influences of water-immersion condition, unload-reloadshear, staged shear and reverse shear for the interface were analyzed.Based on theresults of tests, the shear strength relationship between soil and soil-structure interfacewas discussed, the influences of surface roughness for shear strength of the interfacewas quantitatively analyzed. The constitutive model of disturbed soil-structureinterface (VSRP model) has been established. Numerical implementation of VSRPmodel has been finished through user subroutines. Through numerical calculation, theavailability of the model was verified.According to characteristics of the surface subsidence basin, three-dimensionalsubsidence surface equations have been derived from two-dimensional equations, andimplemented in ABAQUS through Python. The result of numerical calculationindicates that the moving and deformation laws of the three-dimensional equations arebasically the same as those of probability integral method. With a project example, theparameters of the surface subsidence basin were calculated by back analysis. With a project example, the whole three-dimensional elastoplastic model of thefoundation and sluice was established. The selection is studied of the parameters ofMCC model, Mohr-Coulomb model and concrete damage plasticity model. VSRPmodel was used to simulate the interface between the foundation and the sluice. Theinfluence of disturbed soil was considered by changing porosity ratio in VSRP model.Finite element analysis of the sluice within subsidence areas has been finishedconsidering the disturbed soil and without considering the disturbed soil.According to the results of finite element analysis, the reinforcement scheme ofthe sluice chamber was presented by lining with box frame structure. It is showed thatthe scheme is reasonable and has remarkably reinforcing effect, through finite elementanalysis of the reinforced sluice after the influence of mining. Concrete implementscheme of reinforcement and design suggestion for newly-built anti-deformationsluice were presented.