不同埋深条件下隧道围岩压力设计值通用算法  

Universal Calculation Method for Design Values of Tunnel Surrounding Rock Pressure under Different Burial Depth Conditions

作　　者：徐晨 肖明清[1] 谢壁婷 王克金[1] 崔岚 XU Chen;XIAO Mingqing;XIE Biting;WANG Kejin;CUI Lan(China Railway Siyuan Survey and Design Group Co.Ltd,Wuhan,Hubei 430063,China;Institute of Rock and Soil Mechanics,Chinese Academy of Sciences,Wuhan,Hubei 430071,China)

机构地区：[1]中铁第四勘察设计院集团有限公司,武汉430063 [2]中国科学院武汉岩土力学研究所,武汉430071

出　　处：《铁道工程学报》2023年第6期62-68,共7页Journal of Railway Engineering Society

基　　金：国家重点研发计划(2021YFB2600400);中国铁建股份有限公司科研计划(2021-B18);铁四院科技计划(2021K038)。

摘　　要：研究目的:围岩压力的计算是隧道支护结构量化设计的重要环节,目前研究存在明显不足,比如深浅埋分界处围岩压力突变、深埋阶段围岩压力为定值,这些都与实际不相符。为此,本文引入围岩压力设计值概念,提出基于围岩破坏模式的围岩压力设计值通用方法,可为不同埋深下的隧道支护设计提供理论指导。研究结论:(1)本文方法通过计算岩体接近或达到破坏阶段时的极限平衡状态及其破坏区荷载寻求围岩压力设计值,对不同特征隧道具有通用性;(2)隧道由浅入深其支护-破坏区荷载演变规律是不同的,导致其围岩压力特征也有较大区别,浅埋隧道支护-破坏区荷载曲线依次经历全覆土破坏阶段、压剪破坏两侧夹持阶段、洞周压剪破坏阶段、无破坏或局部破坏阶段四阶段,前两个阶段以松弛荷载为主,后两个阶段以形变压力为主,当介于两者之间时,需根据隧道极限平衡状态综合判定,并包络取值,采用本文方法可以保证隧道围岩压力计算结果随埋深变化的连续性;(3)相比于《铁路隧道设计规范》,采用本文方法计算的围岩压力设计值与实际工程结果吻合较好,具备更高的合理性与可靠性。Research purposes:The calculation of surrounding rock pressure is an important link in the quantitative design of tunnel supporting structure.There are obvious deficiencies in the current research,such as the abrupt change of surrounding rock pressure at the boundary of deep and shallow burial and the constant value of surrounding rock pressure at the deep burial stage,which are inconsistent with the practical cases.Therefore,the concept of design value of surrounding rock pressure is introduced in this paper,and a general method of design value of surrounding rock pressure based on failure mode of surrounding rock is proposed,which can provide theoretical guidance for the tunnel design under various burial depths.Research conclusions:(1)The method in this paper seeks the design value of surrounding rock pressure by calculating the ultimate equilibrium state of rock mass approaching or reaching the failure stage and the load in the failure zone,which has the universality to different tunnel characteristics.(2)The load evolution law of the support-failure zone is different in tunnel from shallow to deep,resulting in great differences in the pressure characteristics of surrounding rock.The support-failure zone load curve of shallow buried tunnel goes through four stages successively:full soil failure stage,compression shear failure stage on both sides,compression shear failure stage around the tunnel,no failure stage or local failure stage.The first two stages are dominated by slack load.The latter two stages are dominated by deformation pressure.When it is between the two stages,it is necessary to make a comprehensive judgment according to the tunnel limit equilibrium state and take the envelope value.The method in this paper can ensure the continuity of the calculation results of tunnel surrounding rock pressure changing with the buried depth.(3)Comparing to Code for Design of Railway Tunnel,the design value of surrounding rock pressure calculated by this method agrees better with that in the practical engineerin

关 键 词：埋深 围岩压力设计值 围岩破坏模式 隧道 支护 

分 类 号：U451[建筑科学—桥梁与隧道工程]