Abstract: Consolidation coefficient is an important parameter for geotechnical evaluation, which can be used for soil consolidation analysis. Accurate determination of the consolidation coefficient is the key to estimate the consolidation drainage rate and degree of consolidation and control the accuracy of foundation settlement. Combined with the structure and test principle of the shovel-shaped probe, the dissipation characteristics of the shovel-shaped pore pressure are analyzed. The comparative study of the dissipation results with DMT and CPTU tests are performed. The time factor correction method is used to estimate the consolidation coefficient of saturated soil, and the correction time factor T*us in the spade shaped pore pressure dissipation test results is determined to be 1.13. The engineering application results in Shanghai area show that the theoretical model of spade-shaped pore pressure dissipation can be used to estimate the consolidation coefficient. The horizontal consolidation coefficient of spade pore pressure probe is consistent with that of cone pore pressure. The consolidation coefficient of laboratory test is 3-4 times different from that of spade pore pressure and cone pore pressure in clay, and one order of magnitude different in loose stratum. This research provides a reliable method for estimating the horizontal consolidation coefficient of spade pore pressure through dissipation test.

Key words: Spade Shaped Pore Pressure Probe, Horizontal Consolidation Coefficient, Pore Pressure Dissipation