STUDY ON PERMEABILITY OF FOUNDATION SOIL OF BRIDGES ON LOWER REACHES OF YANGTZE RIVER

The importance to monitor the pore water pressure and to study the permeability of soil under the north anchorage of Jiangyin Yangtze River Highway Bridge is analyzed firstly. According to the observed data, the hydraulic connection characteristics of pore water and river water are analyzed. Then,based on Biot′s consolidation theory,the permeability coefficient of the foundation soil under the north anchorage is obtained by back analysis and varying-scale optimization method. It shows that the permeability coefficient of the soil under the anchorage is 23 percent of the original value. Finally,the rationality of the parameter is verified by comparison btween the straight analysis results and the observed displacement. Parameters of soil will change with the stress condition. Load of huge foundation will affect the permeability of soil. The reduction of permeability of soil is beneficial to the stability of foundation soil.