(1.College of Water Conservancy and Hydropower Engineering, Hohai University, Nanjing 210098, China;2.College of Conservancy and Hydropower Engineering, Gansu Agricultural University, Lanzhou 730070, China;3.Gansu Water Conservancy Engineering Geology Construction Co., Ltd., Lanzhou 730014, China)
Based on the economic design index of single 5% cement, the triaxial test of improved aeolian sand static in mixed cement silt was carried out.The stress-strain and strength characteristics of improved aeolian sand sample under different confining pressures were analyzed, based on which the change law of the viscosity and internal friction angle of different doping ratios, the failure form of improved aeolian sand, and the shear failure mechanism were revealed. The main results show the stress-strain relationship curves of improved aeolian sand are all strain softening curves.The elastic modulus and failure intensity are positively correlated with confining pressure, and elastic modulus reaches to its peak value when the amount of silt mixing is increased to 15%.The value of failure intensity is positively correlated with the amount of silt.The cohesion of modified aeolian sand is the largest under 10% silt mixture, and the internal friction angle increases monotonously with silt mixing amount. The reason is that cement hydrate is wrapped in the surface of sand particles, increasing the surface roughness and forming a network structure in the gap between sand particles.The sand particles are linked together and the relative movement of sand grains is hindered.Incorporating an appropriate amount of silt can fill the gaps between sand particles and hydrates, but excessive silt will restrict the hydration reaction, and at the same time, alkaline ions and hydrates react to produce sodium silicate and sodium aluminate with poor cementing capacity, resulting in a decrease in the overall performance of improved aeolian sand.
刘万乐,田正宏,鲁洋,等.掺水泥粉土的改良风积沙三轴压缩特性[J].水利水电科技进展,2023,43(2):51-57.(LIU Wanle, TIAN Zhenghong, LU Yang, et al. Study on triaxial compression characteristics of improved aeolian sand mixed with cement silt[J]. Advances in Science and Technology of Water Resources,2023,43(2):51-57.(in Chinese))Copy