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Abstract Plastic concrete was widely used in foundation impermeability treatment，especially in impervious wall of high earth rock cofferdam. There were no special guiding regulation and standard about testing method and corresponding structure calculation security evaluation criteria for this material. The triaxial compression test of rock earth material was utilized to obtain the deformation and strength parameters of plastic concrete and stress level was used to measure the safety of concrete impervious wall. But stress level was introduced in triaxial shear state of soil. It adapts for Mohr-Coulomb friction strength theory of granular material safe state. Complex stress state of deep concrete impervious wall material safety check should be carried out through the concrete strength theory. Security criterion which contains multiaxial strength of concrete was introduced. The Baihetan high earth-rock cofferdam whose impervious wall reaches 50 m is taken as an example. Comprehensive three- dimensional finite element calculation was conducted to analyze the safety state of cofferdam. The differences of safety index based on stress level and safety criterion were found. It show that the safety criterion than the stress level can be more sensitive to reflect the impervious wall security state. Stress level could reflect the safety status of the wall when the element positioned in three-dimensional compressed state. The security criterion should be used for safety check when the tensile stress region is obvious.
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Received: 27 May 2013
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2014, Vol. 33 
