SETTLEMENT RESEARCH ON SINGLE PUMPING WELL OF FOUNDATION PIT USING CHANGEABLE PERMEABILITY COEFFICIENT MODEL

Groundwater pumping is an important factor for surface settlement. Based on the Konzeny-Carman seepage model of elastic porous medium, a modified model with changeable permeability coefficient using soil strain is established through consideration of soil internal changes of physical and mechanical properties in the process of the strata deformation due to water pumping. A concept of permeability influential coefficient is then introduced. Using the multi-physical field coupling finite element software COMSOL,a three-dimensional model is built to analyze the variation law among soil settlement and permeability coefficient and influential coefficient. The model is based on the completely coupled method of Darcy seepage and elastic porous medium, and compares the measured settlement data with calculated values. The results show that the calculated values using the modified changeable permeability coefficient model agree fairly well with the actual measured values. This model can better reflect the process of sedimentation causing by pumping.