含水率与粗料含量对砾石土力学性能影响的试验研究  

Experimental research into the effects of moisture contents and coarse-grain contents on the mechanical properties of gravelly soil

作　　者：邵珠山[1] 申国强[1] 王新宇[1] 

机构地区：[1]西安建筑科技大学土木工程学院710055西安

出　　处：《应用力学学报》2015年第2期256-260,354,共5页Chinese Journal of Applied Mechanics

基　　金：国家自然科学基金(10772143);教育部留学回国人员基金([2010]1174)

摘　　要：诸多隧道围岩由宽级配的砾石土组成,砾石土含水率和粗料含量变化时,其力学性能存在较大差异。本文选取集呼高速金盆湾隧道浅埋段具有代表性的砾石土样本进行了室内大型直剪试验,研究了砾石土的力学性能随含水率和粗料含量的变化规律。试验结果表明：当含水率在5.37%～19.19%之间变化时,粘聚力随粗料含量的变化呈相同的变化规律,随着粗料含量增加,粘聚力先迅速下降,后显著增高,在粗料含量为45%左右时取得最小值;当含水率为10%～15%之间的某值时,细料颗粒处于最优含水率状态,当含水率超过最优含水率时,粘聚力显著下降;内摩擦角随粗料含量增加逐渐增加,随含水率增加逐渐降低;结合隧道围岩砾石土的颗粒级配特征,当含水率大于10%时,粘聚力和内摩擦角显著降低,隧道围岩稳定性也随之降低。The surrounding rock of some tunnels is composed of gravelly soil. The mechanical properties of gravelly soil are dramatically affected by moisture contents and coarse-grain contents. In this paper, large-scale direct shear test is employed to study relationship between mechanical properties of gravelly soil and moisture contents and coarse-grain contents by using of gravelly soil collected from Jinpenwan Tunnel. In the case that moisture varies between 5.37%~19.19%, testing results indicate that coarse-grain content presents a similar effect on cohesion, the cohesion decreases with increment of coarse-grain content, and reaches the minimum value when coarse-grain content is equal to 45%. When moisture content varies from 10% to 15%, fine particles achieves optimum water content, and the cohesion declines significantly, the friction angle increases with increment of coarse-grain contents and decreases while the moisture contents is beyond it. Considering the coarse-grain content of Jinpenwan tunnel surrounding rock, its cohesion and friction angle show a significant drop when its moisture contents is larger than 10%, and its stability will also have a significant drop.

关 键 词：砾石土 力学性能 含水率 粗料含量 试验研究 

分 类 号：TU431[建筑科学—岩土工程]