摘要
基于理论分析建立破碎岩体注浆加固体力学模型,通过室内试验制作加固体试样并开展单轴抗压试验,分析破碎岩体含量、破碎程度、界面粗糙程度以及注浆材料黏结性能等因素对加固体强度的影响。试验表明:注浆加固体试样在单轴压缩破坏过程中,其内部石块基本保持完整性,破坏主要产生在交界面以及注浆材料内部;当V_(BP)较大时,在碎石体的阻隔作用下,破裂面无法一次性产生,且多为剪切型破坏;当V_(BP)较小时,压缩破坏过程中直接形成了上下贯通的破裂面,且多为拉断型破坏;对于未加固的破碎岩体,其强度随V_(BP)增加而减小,且强度离散程度较大;加固后其强度随V_(BP)的增大而增大,整体强度大幅提高,同时呈现出明显的线性相关性;加固体强度随碎石数量的增加而减小,二者的线性相关性不显著;加固体强度随着注浆材料黏结强度的增加而增加,随交界面体密度的增加而减小;交界面体密度与黏结强度相互影响,总体强度是二者耦合作用的结果。基于加固体力学模型以及单轴抗压试验数据提出了加固体强度计算公式,该公式考虑了破碎岩体含量、破碎程度、界面粗糙程度以及注浆材料黏结性能等因素对加固体强度的影响。通过与实际试验数据比较,证明了该公式可以较好地对破碎岩体加固强度进行预测。
Based on the results of a theoretical analysis, a mechanical model was proposed for a fractured rock mass with consideration of grouting reinforcement. A uniaxial compressive test was conducted to analyze the influence of various factors, such as the volume of block proportion（VBP）, crushing degree, roughness of the boundary, and cohesive force of the grout material, on the compressive strength of the rock mass. The results reveal that during the failure process, the internal blocks maintain their integrity, and the fracture mainly occurs on the boundary between the blocks and grouting material or in the interior of the grouting material. However, when the VBP is high, a failure surface cannot be generated at once owing to discontinuities in the internal blocks, and a shear failure is observed. For an ungrouted fractured rock mass, the compressive strength decreases as the VBP increases, and the dispersion degree of the test data is large. After grouting reinforcement, the compressive strength increases as the VBP increases and displays a clear linear dependence. The compressive strength decreases as the number of rock blocks increases, and the linear dependence is not obvious. Furthermore, the compressive strength increases as the cohesive force of the grouting material increases, and decreases as the fracture density increases. The overall strength of the rock mass is the result of a coupling effect between the fracture density and cohesive force. Based on the theoretical model and experiment data, a formula that considers the influence of the block amount, fracture degree, interface roughness, and cohesive force of the grouting material was proposed to calculate the compressive strength of the reinforced fractured rock. The accuracy of the formula was evaluated by comparing calculated values with test values.
作者
刘人太
郑卓
李术才
杨红鲁
LIU Ren-tai;ZHENG Zhuo;LI Shu-cai;YANG Hong-lu(Geotechnical and Structural Engineering Research Center,Shandong University,Jinan 250061,Shandong,China)
出处
《中国公路学报》
EI
CAS
CSCD
北大核心
2018年第10期284-291,共8页
China Journal of Highway and Transport
基金
国家自然科学基金项目(51779133)
国家重点研发计划项目(2016YFC0801604)
国家自然科学基金联合基金项目(U1706223)
关键词
隧道工程
注浆加固强度
室内试验
破碎岩体
数据拟合
tunnel engineering
grouting reinforcement strength
laboratory test
fractured rock mass
data fitting
