Experimental study on consolidation characteristics of deep clayey soil in a typical subsidence area of the North China Plain

Land subsidence is an important environmental problem in the North China Plain (NCP). A typical area mainly located on adjoining areas of Beijing and Hebei provinces was selected to study consolidation characteristics deep clayey soil. Clay samples were collected from 14 boreholes at different depths, compression behavior soil analyzed by high-pressure oedometer tests. Results show that deformation amount stabilization time primary stage increase with load but decrease sampling depth. The nonlinear model e -log(p) does not fit well for normally-consolidated soil, log(e+e c )–logp shallow better than hyperbolic fits almost all well. Based statistical theory, equation CE_NCP established calculating relationship between degree factor areas. equations fitted data obtained tests obtain three parameters a, b , which are applied calculations depths 0–100 m, 100–200 200–300 m 300–400 respectively. applicability evaluated comparing it analytical solution Terzaghi’s equation, results showing more suitable calculation solution. Eventually, successfully used estimate a Lang Fang City NCP.