大跨度扁平地下洞室开挖方案研究
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摘要
为获得大跨度扁平地下工程开挖成洞的施工方法,论文结合断面形式为拱形的某超大跨度扁平地下洞室,提出将进深方向的大跨度洞室变成小跨度洞室的纵向跳格、横向分布的开挖方案,采用数值模拟的方法对考虑洞库纵向跳格的开挖顺序、开挖宽度以及两侧导洞的宽度等因素的9种方案进行了对比计算,并从洞库拱顶位、围岩最大剪应变以及锚索、锚杆的受力情况等几个方面对模拟结果进行了系统分析。结果表明:对于超大跨度扁平地下工程采用顺序跳格、逆序回挖的跳格开挖顺序、纵向跳格开挖宽度取15米左右、两侧导洞宽度取10 m左右较为合理,论文研究结果对同类型大跨度地下工程的开挖成洞具重要的参考价值。
This paper aims to investigate the excavation methods used for underground construction with super large span and flat cross section.Considering the large span of the underground chamber with arch section,the excavation scheme was proposed as follows.In the radial direction,the large span chamber was divided into small span chamber.In the longitudinal direction,the excavation sequence was alternate.Then numerical modeling was used to study the influences of excavation sequence,excavation width and pilot tunnel width by nine calculation cases.The simulation results were systematically analyzed from the vault displacement,the maximum shear strain of the surrounding rock,and the stress of the anchor cable and anchor.The results indicate that the alternate excavation sequence in positive and negative directions is reasonable for super large span small sagittal ratio underground cavern.The excavation width of 15 m and the pilot tunnel width of 10 m are recommended.The results in this paper provide a certain references for the similar underground constructions with large span.
This paper aims to investigate the excavation methods used for underground construction with super large span and flat cross section.Considering the large span of the underground chamber with arch section,the excavation scheme was proposed as follows.In the radial direction,the large span chamber was divided into small span chamber.In the longitudinal direction,the excavation sequence was alternate.Then numerical modeling was used to study the influences of excavation sequence,excavation width and pilot tunnel width by nine calculation cases.The simulation results were systematically analyzed from the vault displacement,the maximum shear strain of the surrounding rock,and the stress of the anchor cable and anchor.The results indicate that the alternate excavation sequence in positive and negative directions is reasonable for super large span small sagittal ratio underground cavern.The excavation width of 15 m and the pilot tunnel width of 10 m are recommended.The results in this paper provide a certain references for the similar underground constructions with large span.
引文
[1]Einar B,Arne M M,Gsile S.Support of large rock caverns in Norway[J].Tunnelling and Underground Space Technology,1996,11(1):11-19
[2]Sagefors I,Daerga P A.An excavation method for large vertical cylindrical caverns[J].Tunnelling and Underground Space Technology,1996,11(3):279-285.
[3]孙博,胡功笠,刘新宇,等.大跨度洞库施工开挖稳定性研究[J]地下空间与工程学报,2005,1(5):689-692.
[4]李友华,黄应军,李景元.溪洛渡水电站左岸地下厂房大跨度高边墙开挖施工技术[J].水力发电,2008,34(9):9-14.
[5]王晓伟.龙滩水电站地下厂房大跨度高边墙开挖施工技术[J].广东科技,2009(18):267-268.
[6]刘保国,徐干成.大跨度高边墙地下洞室分层间隔施工方法[J].岩土力学,2011,32(9):2759-2764.
[7]杨明举,常艄东.超大型地下洞室群施工开挖程序及围岩稳定分析[J].西南交通大学学报,2000,35(1):32-35.
[8]赵奎银.大跨度高边墙地下工程施工技术[J].铁道建筑技术,2004(4):34-36.
[9]朱维申,李术才,陈锋.能量耗散模型在大型地下洞群施工顺序优化分析中的应用[J].岩土工程学报,2001,23(3):333-336.
[10]段建立,孙炎光,尤峻.特大跨度扁平洞室开挖施工离散元数值模拟[J].地下空间与工程学报,2013,9(增2):1882-1885.
[2]Sagefors I,Daerga P A.An excavation method for large vertical cylindrical caverns[J].Tunnelling and Underground Space Technology,1996,11(3):279-285.
[3]孙博,胡功笠,刘新宇,等.大跨度洞库施工开挖稳定性研究[J]地下空间与工程学报,2005,1(5):689-692.
[4]李友华,黄应军,李景元.溪洛渡水电站左岸地下厂房大跨度高边墙开挖施工技术[J].水力发电,2008,34(9):9-14.
[5]王晓伟.龙滩水电站地下厂房大跨度高边墙开挖施工技术[J].广东科技,2009(18):267-268.
[6]刘保国,徐干成.大跨度高边墙地下洞室分层间隔施工方法[J].岩土力学,2011,32(9):2759-2764.
[7]杨明举,常艄东.超大型地下洞室群施工开挖程序及围岩稳定分析[J].西南交通大学学报,2000,35(1):32-35.
[8]赵奎银.大跨度高边墙地下工程施工技术[J].铁道建筑技术,2004(4):34-36.
[9]朱维申,李术才,陈锋.能量耗散模型在大型地下洞群施工顺序优化分析中的应用[J].岩土工程学报,2001,23(3):333-336.
[10]段建立,孙炎光,尤峻.特大跨度扁平洞室开挖施工离散元数值模拟[J].地下空间与工程学报,2013,9(增2):1882-1885.