钻孔弹模法在某核岛岩体力学特性中的应用研究  

BORING ELASTIC MODULUS METHOD FOR ROCK MASS MECHANICAL CHARACTERISTICS AT NUCLEAR ISLAND

作　　者：王玉玲[1] 

机构地区：[1]中国能源建设集团广东省电力设计研究院,广州510663

出　　处：《工程地质学报》2013年第1期149-157,共9页Journal of Engineering Geology

摘　　要：钻孔试验法的最大优点是可测试深部岩体力学参数(变形模量或弹性模量),为工程支护设计、工程安全性评价提供最为不可缺少的参数。本文结合某核岛工程,介绍了钻孔弹模法在岩体力学特性的工程应用。研究表明:该方法能够反映岩体结构特征,测试获得的压力变形曲线符合实际,规律性良好。在低压力段,变形发展很快,压力与变形曲线呈非线性;在中压力段,钻孔弹模计的承压板在不断输出增大的压力下与孔壁岩体达到全接触,裂隙闭合,压力与变形曲线接近线性;在高压力段以上,压力与变形曲线在经历了低压力段非线性,中压力段接近线性后最终呈线性。考虑到岩体本身结构质量变化,弹性模量与变形模量会随深度发生一定的变化。经进一步分析核岛岩体变形模量或弹性模量可知,微风化至新鲜的花岗岩岩体各向异性不明显,部分受裂隙和结构面切割影响的测段岩体模量值小于其他测段,岩体模量比值较大,表现出较强的各向异性。最终,本文还给出了微风化至新鲜的花岗岩变形模量值NS向标准值为24.02±1.61GPa,EW向标准值为23.92±1.56GPa,综合变形模量标准值为23.97±1.10GPa;弹性模量值NS向标准值为45.15±2.58GPa;EW向标准值为44.25±2.57GPa;综合弹性模量标准值为44.70±1.79GPa。The biggest advantage of drill test method is to obtain the rock mechanics characteristics such as deform- ation modulus and elastic modulus. They are the crucial parameters for engineering support design and engineering safety evaluation. This paper is based on a nuclear island construction project. It uses the boring elastic modulus method for rock mass mechanics characteristic. It finds that the method is good to reflect the rock mass structure characteristic and the stress-strain curve of test has a relative good regularity. The curve can be described as fol- lows. In low pressure stage, the stress-strain curve is non-linear relation with a quick deformation. In medium pres- sure stage, it needs a certain pressure to force the drill wall and bearing plates of boring elastic modulus equipment to contact completely when the pressure increases and cracks close. In high pressure stage, the stress-strain curve is a linear relation. Meanwhile, with the influence of rock mass structure itself, the deformation modulus and elastic modulus vary at different depths. In a further study on the deformation modulus and elastic modulus at nuclear is- land, it is known that the anisotropy is not evident in granite ranging from weak weathering to fresh. However,some of the test section affected by cracks and joint cutting can show relative low rock mass modulus, bigger rock modulus ratio and stronger in anisotropy. Finally, this paper provides the rock mass modulus in weak weathering to fresh conditions as follows. At the weak weathering condition. The standard value of NS deformation modulus is 24. 02±1.61GPa; the standard value of EW deformation modulus is 23.92±1.56GPa and the comprehensive value of deformation modulus is 23.97±1. IOGPa. At the fresh condition, the standard value of NS elastic modulus is 45.15-±2.58 GPa; the standard value of EW elastic modulus is 44. 25±2. 57GPa and the comprehensive value of e- lastic modulus is 44. 70±1.79GPa.

关 键 词：岩体 力学特性 钻孔弹模法 变形模量 

分 类 号：TU459[建筑科学—岩土工程]