碎石土路基抗剪性能影响因素分析

Analysis on the Influence Factors of the Shear Strength of the Cravel Soil Subgrade

碎石土的抗剪强度是影响碎石土路基稳定性的重要因素,而不同含石量、含水率下的碎石土抗剪强度是不同的,选取公路路基碎石土土样,在不同试验条件下进行碎石土室内直剪试验。试验结果表明:粘聚力随着细粒土含水率的增加呈现先增加后减小的现象,而内摩擦角则随着含水率的增加呈现先缓慢下降后急剧下降的现象。即碎石土达到最佳含水率时,其抗剪强度参数达到最大,这时路基的稳定性最好。粘聚力随着压实度的增加呈现先增加后保持不变的现象,内摩擦角则随着压实度的增加基本保持不变。即施工中应选择最佳含水率和干密度,来达到路基稳定最好效果。碎石含量不同碎石土的抗剪强度系数也不同,随着碎石含量增加粘聚力先增加后减小,内摩擦角则先增加后缓慢下降。在实际施工过程中应控制为最佳含石量。

Gravel soil shear strength is an important factor to affect the stability of the subgrade soil gravel,and different content of stone,water content of gravel soil anti shear strength is different,the selection of highway roadbed gravel soil samples,under different test conditions of gravel Hijimuro Uchinao test. The test results show that the cohesive force of fine grained soil water content decreases after increasing trend from the phenomenon,and internal friction angle is increased with the increase of water content to present the phenomenon of slow drop fell sharply after the first. The best gravel soil water content,the shear strength parameters of the maximum,then the stability of the roadbed is best. Cohesive force with the increase of degree of compaction of present remain unchanged after the first increase phenomenon,internal friction angle is increased with the increase of degree of compaction basic remain unchanged. That should choose the best water content and dry density during construction,to achieve the roadbed stability best effect. Gravel content of gravel soil shear strength coefficient vary,with increase the cohesive force of gravel content increased after the first decreases,and internal friction Angle is increased before they slow down. In actual construction process should be controlled as the best stone content.