Experiment and mathematical model on mechanical properties of natural gravel improving expansive soil
1.Collaborative Innovation Center of Geological Hazards and Ecological Environment in Three Gorges Area in Hubei Province, China Three Gorges University, Yichang, Hubei 443002， China； 2.Civil and Architectural Institute, China Three Gorges University, Yichang, Hubei 443002，China； 3.Yichang Sanxia Airport Road Construction Headquarters, Yichang, Hubei 443002，China； 4.Yichang Transport Bureau, Yichang, Hubei 443002，China； 5.Yichang Hong Yuan Highway Engineering Consulting Supervision Co., Ltd., Yichang, Hubei 443002， China
Abstract：With the expansive soil of Yichang Airport Road reconstruction project as research object, the mechanical properties of soil were improved by the incorporation of natural gravel. The impacts of natural gravel on the expansive soil mechanical properties of expansive soil California bearing ratio, modulus of resilience, unconfined compression strength and shear strength were investigated. The corresponding mathematical model was established. The supplement laboratory tests were conducted to verify the accuracy and precision of mathematical model. The test results show that the mechanical properties of expansive soil are improved significantly by natural grave, and the improved mechanical properties can meet the prescribed value of norms roadbed. The best moisture of expansive soil is decreased, and the maximum dry density of expansive soil is increased with the increasing of natural gravel content. CBR and resilient modulus of expansive soils are effectively improved. The unconfined compressive strength is increased with latter decreasing and reaches a maximum with natural gravel content of 20%. The angle of internal friction shows increasing trend, while the cohesion shows linear decreasing trend. The mechanical index mathematical model is verified by supplement laboratory tests with high accuracy and precision.
2016, Vol. 37 
