Layerwise summation method for ground foundation settlement based on Duncan-Chang constitutive model

Ground foundation settlement analysis is an important content of soil mechanics. Based on the discussion on ground foundation deformation mechanism, firstly, the effects of the buried depth or the initial ground stress, i.e., the preconsolidation stress, on the deformation modulus of foundation soils are considered, and they are divided into two parts: volume stress and partial stress of the initial stress. An idea of step-loading is introduced, and a determinstic method for deformation modulus of ground soils at different depths is established. Secondly, the ground foundation settlement is divided into two parts: settlement caused by additional volume stress and that by additional partial stress, and a ground foundation settlement analysis model is developed. Thirdly, the nonlinear variation characteristics of the ground foundation deformation are considered, the incremental analysis, the Hooke's law and the Duncan-Chang constitutive model are introduced, and the relevant methods for deformation of ground foundation compressed layers caused by the additional volume stress and additional partial stress are put forward. Also, a new ground foundation settlement analysis method based on the Duncan-Chang constitutive model is proposed by adopting the layerwise summation theory. This method can reflect the effects of the initial ground stress and the additional stress on the deformation modulus of the ground soils and avoid the use of the compression curves of ground soils and the static load test curves of ground foundation. Finally, through practical calculation and analysis as well as comparison with the measured settlements and the calculated values of other existing analytical methods, the proposed method meets the requirements of the calculation accuracy and is reasonable and feasible.