高压水直接作用下井壁混凝土真实强度特性研究

Real Strength Characteristics of Shaft Lining Concrete under the Action of High Pressure Water

为研究井壁混凝土在高地下水压作用下强度发展趋势,配制了C60、C70、C80三种高强度等级井壁混凝土,根据养护条件不同将每种强度等级混凝土均分为常规状态试件和密封状态试件,分别在4 MPa、6 MPa、8 MPa、10 MPa水压作用下进行常规三轴加载试验。结果表明:Bresler三参数正八面体强度破坏准则更能准确反映井壁混凝土峰值强度与围压的非线性关系,随着围压的增加井壁混凝土峰值强度具有明显的增强效应,随着混凝土强度等级提高围压敏感性降低;常规状态下井壁混凝土峰值强度随围压增长速率较慢,且比同等级密封状态下井壁混凝土峰值强度大约降低6.3%。

In order to study development trend of strength of shaft lining concrete under the action of ground water pressure, C60, C70, C80 three kinds of high strength grade concrete were prepared. According to different curing condition each strength grade of concrete was divided into general state specimen and sealing state specimen, and under the pressure of 4 MPa, 6 MPa, 8 MPa, 10 MPa, conventional three axis loading test was performed. The results show that： failure criterion of Bresler three parameters is more accurate to reflect nonlinear relationship between shaft lining concrete peak strength and confining pressure, with increase of confining pressure, peak strength of concrete has obvious enhancement effect, and decrease of confining pressure sensitivity is increased with strength grade ; under general condition, peak strength of concrete is slower with increase of confining pressure, and peak strength of general concrete is decreased by about 4.7 % compared with that of the same grade seal.