隧道建设
隧道建設
수도건설
TUNNEL CONSTRUCTION
2014年
3期
216-220
,共5页
水电站%尾水隧洞%大断面%数值模拟%监控量测%结构安全
水電站%尾水隧洞%大斷麵%數值模擬%鑑控量測%結構安全
수전참%미수수동%대단면%수치모의%감공량측%결구안전
hydropower station%tailrace tunnel%large cross-section%numerical simulation%monitoring%structural safety
依托黄金坪水电站尾水隧洞工程，采用数值模拟、现场监测的手段进行了深埋大断面尾水隧洞开挖结构安全研究。研究结果表明：将隧洞断面划分为4层开挖，顶层采用导坑扩挖法，先开挖中部导坑，再向两侧进行刷扩处理，因刷掉的是围岩松动圈外圈的低应力松散带，避免了扰动深部围岩，有利于结构安全；大断面尾水隧洞在分层开挖、支护过程中，围岩最大拉应力为0．86 MPa、最大压应力为6．9 MPa，支护结构最大拉应力为0．6 MPa、最大压应力为5．0 MPa，均远小于允许应力而且不会发生岩爆，围岩和隧洞支护体系在开挖、支护完成后逐步达到稳定状态；围岩多点位移计的现场监控量测结果验证了数值计算结果的正确性，研究方法可为类似工程提供参考。
依託黃金坪水電站尾水隧洞工程，採用數值模擬、現場鑑測的手段進行瞭深埋大斷麵尾水隧洞開挖結構安全研究。研究結果錶明：將隧洞斷麵劃分為4層開挖，頂層採用導坑擴挖法，先開挖中部導坑，再嚮兩側進行刷擴處理，因刷掉的是圍巖鬆動圈外圈的低應力鬆散帶，避免瞭擾動深部圍巖，有利于結構安全；大斷麵尾水隧洞在分層開挖、支護過程中，圍巖最大拉應力為0．86 MPa、最大壓應力為6．9 MPa，支護結構最大拉應力為0．6 MPa、最大壓應力為5．0 MPa，均遠小于允許應力而且不會髮生巖爆，圍巖和隧洞支護體繫在開挖、支護完成後逐步達到穩定狀態；圍巖多點位移計的現場鑑控量測結果驗證瞭數值計算結果的正確性，研究方法可為類似工程提供參攷。
의탁황금평수전참미수수동공정，채용수치모의、현장감측적수단진행료심매대단면미수수동개알결구안전연구。연구결과표명：장수동단면화분위4층개알，정층채용도갱확알법，선개알중부도갱，재향량측진행쇄확처리，인쇄도적시위암송동권외권적저응력송산대，피면료우동심부위암，유리우결구안전；대단면미수수동재분층개알、지호과정중，위암최대랍응력위0．86 MPa、최대압응력위6．9 MPa，지호결구최대랍응력위0．6 MPa、최대압응력위5．0 MPa，균원소우윤허응력이차불회발생암폭，위암화수동지호체계재개알、지호완성후축보체도은정상태；위암다점위이계적현장감공량측결과험증료수치계산결과적정학성，연구방법가위유사공정제공삼고。
In the paper,the structural safety of the deeply-buried large cross-section tailrace tunnel of Huangjinping hyd ropower station is evaluated by means of numerical simulation and field monitoring.The result of this study shows:The tunnel is excavated in four benches,and Bench I is excavated by pilot tunneling method,i.e.,the pilot is excavated before enlarging excavation is made.In this way,the disturbance to the deep surrounding rock is avoided,because the loose surrounding rock with low stress at the outer ring of the surrounding rock is excavated in the enlarging excavation. Therefore,the excavation method adopted is favorable for the structural safety of the tailrace tunnel.In the process of the excavation and supporting of the large cross-section tailrace tunnel,the maximum tensile stress and the maximum com-pressive stress of the surrounding rock are 0.86 MPa and 6.9 MPa respectively,and the maximum tensile stress and the maximum compressive stress of the supporting structure are 0.6 MPa and 5.0 MPa respectively.All of the above-men-tioned values are far less than the allowable stress values,and rock burst would not happen.The surrounding rock and the supporting structure reach stable gradually after the excavation and supporting are finished.The field monitoring re-sults obtained by multi-point displacement gauges verifies the accuracy of the numerical results.The research method de-scribed in the paper can provide reference for similar projects in the future.
