水作用下土石坝黏土心墙抗剪强度衰减规律

Study on Clay Core Wall Shear Strength Attenuation Law of Earth-Rock Dam Under the Action of Water

为得到土石坝黏土心墙在水作用下抗剪强度的衰减规律,依托济南卧虎山水库工程,通过模型分析和现场取样室内试验,研究了土石坝黏土心墙抗剪强度随含水率的衰减规律。研究建立了土石坝黏土心墙抗剪强度衰减的基本模型,推导了黏土抗剪强度的衰减公式,并分析了含水率和压实度对黏性土体抗剪强度参数的影响规律。结果表明:1黏性土体的黏聚力和内摩擦角影响其抗剪强度;2黏性土体抗剪强度衰减公式由强度参数的待定系数及其表达式构成,可分别通过室内击实试验求解;3压实度一定时,黏聚力随含水率的增大而减小,且最大内摩擦角对应最优含水率;压实度的增大引起抗剪强度增大,但内摩擦角对抗剪强度的影响不显著。

In order to obtain the clay core wall shear strength attenuation law of earth rock dam under the action of water,relying on Jinan Wohushan Reservoir project,through the model analysis and laboratory test of field sampling,the earth rock dam clay core wall shear strength attenuation with the moisture content was studied. Research established basic model of the earth rock dam clay core wall shear strength attenuation under the action of water,deduced the shear strength attenuation formula of the clay and analyzed the influence law of soil moisture content and compaction on clay shear strength parameters. The results are as follows：1）the cohesion and internal friction angle of clay affect the shear strength;2）shear strength attenuation formula are composed of undetermined coefficient and expression of shear strength parameters,which can be solved through beating experiment;3）cohesion decreases with the increase of moisture content when com pactness is defined and the maximum internal friction angle are corresponding to the optimum moisture content;the increase of compactness causes the increase of shear strength,but the internal friction angle affects the shear strength little.