含水率和压实度对路基填土力学特性的影响

Effects of Water Content and Compaction Degree on Mechanical Characteristics of Roadbed

路基填土的强度特性和压缩特性直接关系到路基的长期稳定性。为研究含水率和压实度对路基填土的力学特性的影响,对某路基填土进行了直剪和压缩试验,得到了不同初始含水率和压实度下土体的抗剪强度指标和压缩特性指标,讨论了粘聚力、内摩擦角和压缩系数随含水率和压实度的变化规律,并从水分变化和土体结构差异的角度分析了其影响机理。结果表明:相同含水率下,粘聚力随压实度的增大而增大;相同压实度下,粘聚力在最优含水率ωop附近有峰值,当ω>ωop时,粘聚力急剧减小。相同含水率下,内摩擦φ随压实度的增大而增大;ω<ωop时,φ随压实度的变化率较小,反之则较大。路基填土的压缩系数随压实度的增大而减小,随含水率的增大而增大。

The strength and compression characteristics are directly related to the long-term stability of roadbed. In order to study the effects of water content and compaction degree on the mechanical characteristics of roadbed, the direct shear tests and compression tests are carried out for a specific roadbed soil. The shearing strength and compression properties of the roadbed soil are obtained in different water contents and compaction degrees, the relationships of cohesion, internal friction angle and compressive coefficient with water content and compaction degree are discussed, and the mechanism is analyzed from soil structures and water content difference. The test results show that when the water content is the same, the soil cohesion increases with the compaction degree increasing. For same compaction degree, the soil cohesion reaches the peak value around the optimum water content ωop and decreases sharply when ω 〉 ωop ~ The internal friction angle in- creases with the increase of compaction degree when the water content is the same. The increasing amplification of Ф decreases with the increase of compaction degree when ω 〈 ωop, and vice versa. The compressive coefficient decreases when the compaction degree increases, while increases with the water content increases.