深埋富水全风化花岗岩中长距离水平旋喷桩试验与分析

厦深铁路梁山隧道因在DK96+495~DK96+535段穿越L7深埋富水全风化花岗岩软弱带,为全线的控制性工程。为穿越该软弱带,经过技术与经济论证,最后决定采用全环水平旋喷桩超前预加固技术。为确保长度达40 m的水平旋喷桩在该地层中的可实施性,进行了本次现场试验。通过试验,得到试验桩平均桩径51.5 cm,平均桩长43 m,桩体平均强度3.2 MPa,并根据试验结果改进了部分施工工艺。采用该技术顺利通过了L7深埋富水全风化花岗岩软弱带,并施作了衬砌结构,实践证明,通过试验得到的长距离水平旋喷桩加固技术是成功的。

Experiment and Analysis of Long and Middle Distance Horizontal Rotary Jet Grouting Pile in Deep Buried Water-Rich Completely Weathered Granite

The Liangshan Tunnel on DK96 ＋ 495 ＋ DK96 ＋ 535 of Xianmen-Shenzheng railway goes through weak zone of deep buried water rich complete weathered granite therefore viewed as the control project of the line. To go through the soft weak zone, by technical and economical calculation, finally the advanced consolidation technology of full ring horizontal rotary jet grouting pile is adopted. To ensure the feasibility of 40 meters long horizontal rotary jet grouting in the stratum, the on site experiment is carried out. The test results show the average pile diameter is 51.5, the average pile length is 43 meters and average strength is 3.2 MPa. Based on the results, part of the construction process is improved. The technique enable the tunnel to go through the L7 weak zone of deep buried water rich completely weathered granite which is reinforced with lining structure. The practice proves the feasibility of the long distance horizontal rotary grouting jet proposed in the paper.