The uniaxial compressive and tensile tests of frozen saturated clay in Shanghai area

摘要

The compressive and tensile strengths of frozen clay are important parameters for frozen wall design in artificial freezing excavation of tunnels and foundation pits. Up to now, nobody has conducted the compressive and tensile test of frozen clays in Shanghai area. In this paper, the unconfined compressive and tensile tests of frozen clay specimens drilled from the soil horizons 3-5 in Shanghai area were conducted in Zwick-Z020kN High-low Temperature Materials Testing Machine and Frozen Soil Triaxial Testing Machine, the corresponding constitutive equations were suggested; the temperature-unconfined uniaxial compressive strength relation was discussed; the strain rate-unconfined uniaxial compressive strength and strain rate-uniaxial tensile strength relations were studied. The relation between moisture content, dry density and unconfined uniaxial compressive strength was analyzed, too. In addition, the uniaxial compressive elastic modulus of Shanghai frozen clays and its influence factors were discussed. The research work of the current paper is very helpful for the design and theoretical studies of artificial freezing excavation in soft soil areas.