Kim Ji-Won, Chong Song-Hun, Cho Gye-Chun
Department of Civil and Environmental Engineering, Korea Advanced Institute of Science and Technology, 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Korea.
Department of Civil Engineering, Sunchon National University, 225 Jungang-ro, Suncheon 57922, Korea.
Materials (Basel). 2018 Mar 29;11(4):524. doi: 10.3390/ma11040524.
Grouting of fractured rock mass prior to excavation results in grout-filled discontinuities that govern the deformation characteristics of a site. The influence of joint characteristics on the properties of grouted rocks is important in assessing the effects of grouting on jointed rock mass. However, grouting remains a predominantly empirical practice and the effects of grouting on rock joint behavior and material properties have yet to be accurately assessed. Granular materials, including jointed rocks, typically display nonlinear strain-dependent responses that can be characterized by the shear modulus degradation curve. In this study, the effects of grouting on the strain-dependent shear stiffness of jointed rock mass were investigated at the small-strain (below 10) and mid-strain (10 to 10) ranges using the quasi-static resonant column test and rock mass dynamic test devices. The effects of curing time, axial stress, initial joint roughness, and grouted joint thickness were examined. The results show that (1) grouting of rock joints leads to decreased stress sensitivity and increased small-strain shear stiffness for all tested samples; (2) the grouted rock samples display similar modulus degradation characteristics as the applied grout material; (3) the initial joint roughness determines the stress-dependent behaviors and general stiffness range of the jointed and grouted rocks, but the strain-dependent behaviors are dependent on the properties of the grout material; (4) increased grouted joint thickness results in larger contribution of the grout properties in the overall grouted rock mass.
在开挖前对裂隙岩体进行灌浆会形成充满浆液的不连续面，这些不连续面决定了场地的变形特性。节理特性对灌浆岩石性能的影响在评估灌浆对节理岩体的效果时很重要。然而，灌浆仍然主要是一种经验性做法，灌浆对岩石节理行为和材料性能的影响尚未得到准确评估。包括节理岩石在内的粒状材料通常表现出非线性应变相关响应，可用剪切模量衰减曲线来表征。在本研究中，使用准静态共振柱试验和岩体动力试验装置，在小应变（低于10）和中应变（10至10）范围内研究了灌浆对节理岩体应变相关剪切刚度的影响。研究了养护时间、轴向应力、初始节理粗糙度和灌浆节理厚度的影响。结果表明：（1）对岩石节理进行灌浆会导致所有测试样品的应力敏感性降低和小应变剪切刚度增加；（2）灌浆后的岩石样品表现出与所用灌浆材料相似的模量衰减特性；（3）初始节理粗糙度决定节理和灌浆岩石的应力相关行为和一般刚度范围，但应变相关行为取决于灌浆材料的性能；（4）灌浆节理厚度增加会导致灌浆材料在整个灌浆岩体中的贡献更大。
