基于微震能量演化的大岗山右岸边坡抗剪洞加固效果研究  

Reinforcement effect of anti-shear tunnels of Dagangshan right bank slope based on microseismic energy evolution

作　　者：庄端阳 唐春安[1,2] 梁正召[1,2] 马克[2,3] 

机构地区：[1]大连理工大学海岸和近海工程国家重点实验室,辽宁大连116023 [2]大连理工大学岩石破裂与失稳研究中心,辽宁大连116024 [3]力软科技(大连)股份有限公司,辽宁大连116600

出　　处：《岩土工程学报》2017年第5期868-878,共11页Chinese Journal of Geotechnical Engineering

基　　金：国家重点基础研究发展计划("973"计划)项目(2014CB047100);国家自然科学基金项目(51274053)

摘　　要：微震监测技术在岩体工程监测中获得了广泛的应用,但如何依据微震监测数据来评价岩体工程的稳定性,至今还存在很多问题。以大岗山右岸边坡工程为研究背景,基于定量微震学原理,采用微震能量密度来综合反映岩体微破裂分布特征,并在理论上推导微震能量–频度关系,提出以b_ε值来表征岩体微破裂变形程度,进一步研究了该边坡抗剪洞加固前后边坡岩体微震能量转移特征、震源机制、变形特性及其稳定性演化规律。研究结果表明,微震能量密度可以帮助识别边坡潜在危险区域,能量–频度关系中的b_ε值的变化揭示了边坡微破裂与变形的演化过程;抗剪洞加固后边坡微震事件活动率和能量密度均明显降低,边坡受力性能明显改善;边坡开挖期间抗剪洞加固区岩体微震的b_ε值小幅降低,并在抗剪洞加固后有所增加,表明抗剪洞抑制了岩体微破裂及变形,提高了边坡稳定性。通过对比工程现场变形监测结果,验证了方法的可靠性。提出的微震能量密度及能量–频度关系相结合的评价方法,丰富了工程岩体稳定性微震分析方法,可为类似岩质边坡加固措施的选择及稳定性分析提供参考。Microseismic monitoring technology has been widely used in rock mass engineering monitoring. There are still many problems in stability evaluation of rock mass engineering using the microseismic data. In this study, microseismic energy density is proposed to characterize the micro-crack distributions of rock mass based on the quantitative seismology. Besides, the energy-frequency relation is derived theoretically and the bε value is used to represent the micro-cracking deformation. Then the microseismic energy transference and evolutions of focal mechanism, micro-cracking deformation and stability of Dagangshan right bank slope before and after reinforcement by anti-shear tunnels are discussed. Some conclusions are drawn as follows： Firstly, potential dangerous area of the slope can be determined using the microseismic energy density, and evolutions of micro-cracking deformation and rock stability are revealed by tracking the variation of b, value in the energy-frequency relation. Secondly, the microseismic event rate and energy density decrease significantly after reinforcement, and its mechanical behavior is obviously improved. Finally, the b6 value of reinforced rock masses decreases slightly along with slope excavation and increases after reinforcement, which demonstrates that the micro-cracking deformation is controlled and the stability is improved after reinforcement, and these are in accordance with the monitoring results of slope deformation,validating the reliability of the proposed method, which enriches the microseismic analysis methods for rock mass engineering stability. It may provide references for choosing reinforcement methods and analyzing stability in similar rock slopes.

关 键 词：岩石高边坡 抗剪洞 能量密度 能量–频度关系 能量转移 稳定性 

分 类 号：TU457[建筑科学—岩土工程]