摘要
脆性围岩中常常发生张拉破坏,有必要对检验脆性围岩的抗张拉承载能力的判据进行研究。在此基础上对张拉破坏判据如何在工程应用进行了研究。采用数值分析对比分析了常见断面形式的较大张应变区域,为断面的合理选型提供了参考。提出了基于张应变破坏区的锚杆设计方法,认为锚杆的设计长度应略长于最终的张应变破坏区的厚度。最后将张拉破坏判据应用于终南山2号超大直径深竖井工程稳定性分析中。通过三维有限元模拟分析表明:按照张拉破坏判据,秦岭终南山2号竖井I级围岩在开挖后,仅进行喷射混凝土支护,便可保持稳定;Ⅲ级围岩在施加按张应变破坏区设计的锚杆后,围岩也可以保持稳定。
Tensile failure often happens in brittle surrounding rock.It is necessary to establish the criterion for validating the tension bearing capacity of brittle surrounding rock.On this basis,engineering application of tensile failure criterion was discussed.The areas of large tensile strain on normal cross-section was compared and analyzed by numerical analysis to provide a reference for choosing the proper cross-section.The design method of anchor based on area of tensile strain failure was presented.It is considered that the design length of anchor should be slightly longer than the ultimately thickness of area of tensile strain failure.Finally,the tensile failure criterion was applied to the stability analysis of the 2nd large diameter deep shaft of Zhongnanshan road tunnel.The 3D FEM analytical result shows that the first class surrounding rock of the 2nd shaft of Zhongnanshan road tunnel would be stabile after being supported by shotcrete only and the third class surrounding rock would be stabile after being supported by anchor designed for the area of tensile strain failure according to the tensile failure criterion.
出处
《公路交通科技》
CAS
CSCD
北大核心
2010年第3期103-107,共5页
Journal of Highway and Transportation Research and Development
基金
上海市重点学科建设项目(B308)
关键词
隧道工程
张拉破坏判据
数值分析
超大直径深竖井
锚杆设计
tunnel engineering
tensile failure criterion
numeric analysis
super-large diameter deep shaft
anchor design
