摘要
采用三轴平面应变巷道模型试验系统,运用数字照相进行变形量测的方法,研究深埋应力场中不同节理倾角和密度的断续节理岩体中开挖巷道围岩破裂区的形成和扩展机理,对巷道的稳定性进行定量与定性评价。研究结果表明：节理密度决定岩体的承载能力,控制巷道围岩的稳定性;在相同应力场中,节理岩体与完整岩体的变形量和稳定性差异显著,完整岩体的变形量小、稳定性好。当巷道收敛率达到2.46%之前,巷道围岩处于弹塑性变形阶段,理论上可以不支护;当巷道收敛率为2.46%~5.00%时,围岩中产生破裂区并快速增大,此时围岩尚有一定的自稳能力,但必须支护以维持稳定,常规的支护方案均可保证巷道的安全和使用功能;当巷道收敛率超过5.00%时,围岩破裂区的发展趋缓,而巷道会发生片帮或冒顶事故,此时围岩已失去自稳能力,需要加强支护来人工稳定;如果延迟支护或支护不当,维持巷道的稳定会越来越困难;当巷道收敛率达到22.80%时,巷道将完全失去安全和使用功能,并丧失可人工稳定的可能。
By adopting the triaxial plane strain system for roadway model test and the digital photogrammetry for deformation measurement,the mechanism of generation and propagation of broken rock zone and roadway stability in jointed rock mass with different joint angles and joint densities were quantitatively studied in deep stress field.The results show that joint density affects largely the carrying capacity of the rock mass and has full control of the stability of surrounding rock.The amount of deformation and stability performance between jointed rock mass and intact rock are significantly different in same stress field,and intact rock exhibits a small amount deformation and better stability performance.It is not technically necessary to support the roadway because the rock mass is in the elastic and plastic deformation stage before the convergence percent of roadway exceeds 2.46%.When the convergence percent is in the range of 2.46% to 5.00%,the broken rock zone will be generated firstly in surrounding rock and increases rapidly,but there is yet a certain self-stability capacity of surrounding rock.However,artificial stability is obligatory at this time.As long as the convergence percent does not exceed 5.00%,the general supporting method can ensure the roadway stability and it need not to adopt reinforced support.When the convergence percent is more than 5.00%,the broken rock zone would be enlarged slowly,meanwhile rib spalling and roof caving would occur in turn on the roadway.The self-stability capacity of surrounding rock has lost synchronously and the reinforced support must be taken for the roadway stability.If the support is delayed or inappropriate,to maintain the roadway stability will be progressively difficult.If the convergence percent reaches 22.80%,the roadway will be destroyed completely and lose the safety and use function,and ultimately lose the possibility of artificial stability.
出处
《中南大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2013年第7期2910-2918,共9页
Journal of Central South University:Science and Technology
基金
国家重点基础研究发展计划("973"计划)项目(2002CB412700)
关键词
模型试验
节理密度和角度
围岩破裂区
收敛率
巷道稳定性
model test
joint density and angle
broken rock zone
convergence percent
roadway stability
