浅埋大跨径软土地层公路隧道下穿既有铁路车站路基施工技术

发布时间：2018-12-18 09:24

【摘要】：针对浅埋大跨径公路隧道近距离下穿既有铁路车站安全系数低的现状,文章以东孚隧道下穿既有厦深铁路站场区段工程实例为依托,通过理论分析、技术比选,提出了以"运用管幕法对隧道开挖方向围岩土体进行加固+挖孔桩上设承台作为临时支墩+挖孔桩结构选型与安全性检算+架设24 m D型便梁将既有铁路轨道托起+纵、横抬梁加固钢轨+弧形导洞预留核心土开挖+加固效果沉降监测与分析"相结合的施工技术总体方案。工程应用效果表明,加固效果显著,可快速、有效地限制隧道下穿区段地层沉降量,拱部管幕可以起到承载作用,D型便梁可减弱管幕体系所承受的外部荷载,大大提高了下穿隧道与既有铁路运营的安全系数,达到了预期效果。
[Abstract]:In view of the low safety factor of shallow buried long span highway tunnel passing through the existing railway station at short distance, this paper, based on the actual engineering example of the Dongfu tunnel passing through the existing Xia-Shen railway station yard, through theoretical analysis, compares and selects the technology. In this paper, it is put forward that using the method of pipe curtain to reinforce the surrounding rock and soil in the direction of tunnel excavation, the pile cap is installed on the excavation pile as the temporary support pier, and the structure selection and safety check and calculation are used to set up the 24m D beam to lift the existing railway track longitudinal. The overall scheme of construction technology combined with the settlement monitoring and analysis of the effect of excavation and reinforcement of the reserved core soil in the arc guide tunnel reinforced by the transverse lifting beam is presented in this paper. The results of engineering application show that the reinforcement effect is remarkable, can be quickly and effectively limited the amount of ground settlement in the underpass section of the tunnel, the arch pipe curtain can play a bearing role, and the D-type beam can weaken the external load of the tube-curtain system. The safety factor of the underpass tunnel and the existing railway is greatly improved, and the expected effect is achieved.
【作者单位】：天津大学;
【分类号】：U455.4

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