岩石力学与工程学报
巖石力學與工程學報
암석역학여공정학보
CHINESE JOURNAL OF ROCK MECHANICS AND ENGINEERING
2013年
z2期
3501-3508
,共8页
李生杰%谢永利%吴丹泽%朱小明
李生傑%謝永利%吳丹澤%硃小明
리생걸%사영리%오단택%주소명
岩石力学%公路隧道%煤系地层%软岩大变形
巖石力學%公路隧道%煤繫地層%軟巖大變形
암석역학%공로수도%매계지층%연암대변형
rock mechanics%highway tunnel%coal strata%large deformation of soft rockmass
高速公路安远隧道穿越煤系地层,围岩主要由炭质页岩、煤线、泥岩夹层组成,炭质页岩试件单轴抗压强度为3.9~4.8 MPa。开展地应力测量,测量结果表明隧址区最大水平主应力为8~10 MPa,水平应力作用占主导。通过现场监测以及数值模拟分析,分析围岩大变形的特征,总结围岩大变形产生的原因,主要有:(1)围岩强度低且易膨胀;(2)相对岩体强度,地应力较高;(3)水理作用;(4)施工不当。在此基础上探讨变形机制。提出相应的处治措施:开挖后迅速封闭掌子面,设置临时支撑,施作长锚杆和注浆小导管控制变形,待变形稳定后适时进行拱圈更换,加密钢拱架间距,及时施作仰拱及二衬衬砌。现场监测结果显示,上述措施实施后,取得较为满意的效果。
高速公路安遠隧道穿越煤繫地層,圍巖主要由炭質頁巖、煤線、泥巖夾層組成,炭質頁巖試件單軸抗壓彊度為3.9~4.8 MPa。開展地應力測量,測量結果錶明隧阯區最大水平主應力為8~10 MPa,水平應力作用佔主導。通過現場鑑測以及數值模擬分析,分析圍巖大變形的特徵,總結圍巖大變形產生的原因,主要有:(1)圍巖彊度低且易膨脹;(2)相對巖體彊度,地應力較高;(3)水理作用;(4)施工不噹。在此基礎上探討變形機製。提齣相應的處治措施:開挖後迅速封閉掌子麵,設置臨時支撐,施作長錨桿和註漿小導管控製變形,待變形穩定後適時進行拱圈更換,加密鋼拱架間距,及時施作仰拱及二襯襯砌。現場鑑測結果顯示,上述措施實施後,取得較為滿意的效果。
고속공로안원수도천월매계지층,위암주요유탄질혈암、매선、니암협층조성,탄질혈암시건단축항압강도위3.9~4.8 MPa。개전지응력측량,측량결과표명수지구최대수평주응력위8~10 MPa,수평응력작용점주도。통과현장감측이급수치모의분석,분석위암대변형적특정,총결위암대변형산생적원인,주요유:(1)위암강도저차역팽창;(2)상대암체강도,지응력교고;(3)수리작용;(4)시공불당。재차기출상탐토변형궤제。제출상응적처치조시:개알후신속봉폐장자면,설치림시지탱,시작장묘간화주장소도관공제변형,대변형은정후괄시진행공권경환,가밀강공가간거,급시시작앙공급이츤츤체。현장감측결과현시,상술조시실시후,취득교위만의적효과。
Surrounding rock of Anyuan highway tunnel through coal strata is made of carbonaceous shale,coal line and mudstone weak interlayer. The uniaxial compressive strength of the carbonaceous shale specimens are 3.9-4.8 MPa. The geostress measurement is carried out,and the results show that the maximum horizontal principal stress is 8-10 MPa,and the horizontal principal stress is dominant in the area of tunnel. Based on the on-site monitoring and numerical simulation,the characteristics of surrounding rock deformation are analyzed. The reasons for large deformation are summarized as follows:(1) The strength of surrounding rock is low and the rock swells easily;(2) The level of geostress is high as to the low strength of rockmass;(3) Water effect;(4) Improper construction. The mechanism of large deformation is discussed also. The countermeasures are proposed as follows:the tunnel face should be closed quickly after excavation,then the temporary support is set up,long bolts and grouting pipe are used to control the deformation,the arch is replaced after deformation become stable,the spacing of steel arch is reduced,and finally,invert and inner lining are applied timely. According to the measurement results,it is shown that the treatment measures are effective.