摘要
为了揭示不同围岩类别隧道高预应力锚固支护的控制机制,解决复杂地质条件下支护结构破坏、围岩变形难控制及高预应力应用不足等问题,本文通过结合锚杆拉伸力学性能和FLAC3D中的Cable单元,提出锚杆单元失效断裂判据,利用Fish语言修正Cable本构方程,开发可破断式锚杆数值模型计算程序并建立锚杆拉伸-可破断数值模型,实现锚杆拉伸受力破断的数值模拟;同时开展不同围岩类别(Ⅲ、Ⅳ、Ⅴ级)隧道预应力支护控制数值试验研究。结果表明:高预应力可有效降低开挖后围岩的应力集中程度,减小围岩变形量及塑性区面积,显著改善围岩控制效果;随着预应力增加,Ⅴ级围岩条件下隧道围岩的应力集中降低率、变形平均控制率、塑性区面积控制率等指标的增幅远大于Ⅲ级和Ⅳ级围岩。本文成果可为深部隧道预应力锚固支护设计与施工提供借鉴与参考。
To reveal the control mechanism of high prestressed anchorage support in tunnels under different surrounding rock classifications and solve the problems such as support structure failure,difficulties in controlling surrounding rock deformation,and insufficient application of high prestress under complex geological conditions,in combination with the tensile mechanical properties of anchor rods and the Cable element in FLAC3D,a failure and fracture criterion for anchor rod elements is proposed and the Cable constitutive equation is modified by means of the Fish language,to develop a numerical model calculation program for breakable anchor rods and to build a tensile-breakable numerical model for anchor rods,realizing numerical simulation of tensile failure under stress and to conduct numerical experiments on prestressed support control for tunnels under different surrounding rock classification(Class Ⅲ,Ⅳ,and Ⅴ).The results show that high prestress can effectively reduce the stress concentration degree in surrounding rock after excavation,decrease deformation and the area of plastic zones,and significantly improve the control effect on surrounding rock.With increasing prestress,the increasing rates of indicators such as stress concentration reduction rate,average deformation control rate,and plastic zone area control rate under Class V surrounding rock conditions are significantly greater than those under Class Ⅲ and Ⅳ surrounding rock conditions.The findings of this study can provide reference and guidance for the design and construction of prestressed anchorage support in deep tunnels.
作者
于斌
张慧雪
李义钊
YU Bin;ZHANG Huixue;LI Yizhao(Shandong Dezhexin Project Management Co.,Ltd.,Jinan 250002,Shandong,China;Shandong Construction Supervision and Consulting Co.,Ltd.,Jinan 250002,Shandong,China;Shandong Provincial Construction Training and Professional Qualification Registration Center,Jinan 250002,Shandong,China)
出处
《工程建设》
2026年第1期46-55,共10页
Engineering Construction
关键词
围岩类别
预应力锚杆
本构方程
数值试验
控制机制
surrounding rock classification
prestressed anchor rod
constitutive equation
numerical experiment
control mechanism
