现代隧道技术
現代隧道技術
현대수도기술
MODERN TUNNELLING TECHNOLOGY
2014年
6期
12-18
,共7页
吴金刚%宋艳彬%陈仁东%陈道松
吳金剛%宋豔彬%陳仁東%陳道鬆
오금강%송염빈%진인동%진도송
公路隧道%洞口加强段%支护结构%荷载特点%作用机理
公路隧道%洞口加彊段%支護結構%荷載特點%作用機理
공로수도%동구가강단%지호결구%하재특점%작용궤리
Highway tunnel%Reinforcement at the portal section%Support structure%Loading characteristics%Ac-tion mechanism
结合目前公路隧道洞口段支护结构加强设计存在的问题，文章从洞口段与洞身浅埋段的围岩特性、荷载作用特点入手，基于超前管棚、初期支护、二次衬砌的作用机理，分析了支护结构在不同围岩条件下的作用特点，给出了洞口加强段和洞身浅埋段衬砌设计的合理化建议。主要得到以下结论：（1）洞口段围岩破碎，自稳能力差，超前支护为围岩早期稳定提供条件，初期支护为主要承载结构，二次衬砌承担部分荷载并提供一定的安全储备；由于洞口段衬砌上覆荷载较洞身浅埋段小得多，不宜加强二次衬砌，因此洞口加强段衬砌设计应以加强超前支护与初期支护为主。（2）洞身浅埋段围岩较完整，有一定的自稳能力，二次衬砌为主要承载结构，初期支护主要发挥与围岩粘附的协同作用；洞身浅埋段衬砌设计应以加强二次衬砌为主，并要控制施作时机。
結閤目前公路隧道洞口段支護結構加彊設計存在的問題，文章從洞口段與洞身淺埋段的圍巖特性、荷載作用特點入手，基于超前管棚、初期支護、二次襯砌的作用機理，分析瞭支護結構在不同圍巖條件下的作用特點，給齣瞭洞口加彊段和洞身淺埋段襯砌設計的閤理化建議。主要得到以下結論：（1）洞口段圍巖破碎，自穩能力差，超前支護為圍巖早期穩定提供條件，初期支護為主要承載結構，二次襯砌承擔部分荷載併提供一定的安全儲備；由于洞口段襯砌上覆荷載較洞身淺埋段小得多，不宜加彊二次襯砌，因此洞口加彊段襯砌設計應以加彊超前支護與初期支護為主。（2）洞身淺埋段圍巖較完整，有一定的自穩能力，二次襯砌為主要承載結構，初期支護主要髮揮與圍巖粘附的協同作用；洞身淺埋段襯砌設計應以加彊二次襯砌為主，併要控製施作時機。
결합목전공로수도동구단지호결구가강설계존재적문제，문장종동구단여동신천매단적위암특성、하재작용특점입수，기우초전관붕、초기지호、이차츤체적작용궤리，분석료지호결구재불동위암조건하적작용특점，급출료동구가강단화동신천매단츤체설계적합이화건의。주요득도이하결론：（1）동구단위암파쇄，자은능력차，초전지호위위암조기은정제공조건，초기지호위주요승재결구，이차츤체승담부분하재병제공일정적안전저비；유우동구단츤체상복하재교동신천매단소득다，불의가강이차츤체，인차동구가강단츤체설계응이가강초전지호여초기지호위주。（2）동신천매단위암교완정，유일정적자은능력，이차츤체위주요승재결구，초기지호주요발휘여위암점부적협동작용；동신천매단츤체설계응이가강이차츤체위주，병요공제시작시궤。
In light of the existing problems regarding the reinforcement design of support at the portal sections of highway tunnels, and based on the characteristics of surrounding rock and its loading at the portal and shallow-buried tunnel sections, this paper analyzes supporting features under different rock conditions by considering the action mechanisms of pipe-roof support, primary support, and secondary linings, and gives relevant suggestions for the above two sections. The results show that due to fractured surrounding rock and its poor self-stability at the portal section, the advance support plays an important role in enhancing the early stability of the rock, the primary support serves as the main bearing structure, and the secondary lining can be used to share part of load with a certain safety reserve. Thus, for the portal section it is better to strengthen the advance support and the primary support instead of the secondary lining, since the loads at the portal section are less than that at the shallow-buried section. Additionally, because of the intact surrounding rock and its certain self-stability at the shallow-buried section, the secondary lining serves as the main bearing structure and the primary support gives play to adhesion for better coordination between the surrounding rock and the support structure. Consequently, it is better to strengthen the secondary lining at the shallow-buried section and choose the best time for installation.
