陕南坡改梯填筑土的击实特性与抗剪强度试验研究

陕南梯地建设中存在的主要问题是土坎梯地垮坎严重,为了从土性方面探索梯地垮坎防治的途径与措施,该文按土工试验规程规定的方法测定了土料的主要物性物态指标,研究了修地筑坎土料的击实特性和抗剪强度与主要物性物态指标之间的关系。研究表明,陕南几种典型筑坎土料的最大干密度和相应的最优含水量与土粒平均粒径d₅₀、小于0.005mm土粒含量P、塑性指数I_p、塑限含水量ω_p之间存在显著的相关关系:填筑土的抗剪强度主要受含水量控制,其强度指标与填筑含水量之间存在显著的线性负相关关系。分析表明,含水量对抗剪强度的削弱效应远大于干密度对抗剪强度的加强度效应

Experimental Study on Soil Compact Characteristics and Its Shearing Strength in Changing Slope Fields into Terrace in South Shaanxi Province

The main problem existing in South Shaanxi Province terrace construction is serous collapse of terrace bank. According to the prescribed methods of soil engineering test regulations, the major indexes of physical properties and physical states were measured, and the relationships among the compact characteristics together with shearing strength of the soils and its major indexes of physical properties and physical states were researched for discussion on controlled channel and measures of terrace bank collapse from soil property. The researches show that there exist notable interrelationships among the maximum dry bulk density, optimum moisture content and plastic limited moisture, plastic property index, average grain diameter percentage of soil grain less than 0.005 mm in South Shaanxi Province terrace ridge soils. The shearing strength of constructing soils is mainly controlled by moisture content, and there is markable linear and negative correlation between indexes of the soil shearing strength and moisture content in soil. Analysis shows that the effect of moisture weakening shearing strength is more than the effect of dry bulk density reinforcing shearing strength.