新管幕法三角区注浆加固技术研究与应用

Research and Application of Grouting Reinforcement Technology in Triangle Area of New Pipe Curtain Method

新建铁路线交叉穿越既有铁路线的施工已经成为铁道部安全管理的重点,新建隧道下穿既有线施工,工程安全风险高、制约因素多、工程环境复杂。传统下穿铁路施工方法,需要对既有线进行封锁,送样就使正常的铁路行车受到了影响,进而使地方的交通和经济发展受到制约。新管幕法可以很好的解决以上问题,通对新管幕法三角区注浆加固技术研究得到了以下结论 :(1)测量放样准确,钢管上侧切割线由下侧延伸上去,注浆孔在切割线内侧,保证了后续工作的施工质量;(2)送杆时钻杆深度满足要求,高压旋喷时钻杆的倾斜角度上下排不一致,上排孔保持水平向上15°～30°,下排孔为水平向下30°～60°,保证了旋喷桩的长度;(3)高压旋喷时旋转角度和旋转速度与提升速度相匹配,喷嘴大小合理,注浆泵的转速和注浆流量成正比,选择合适的喷嘴和注浆泵转速保证注浆压力,喷嘴大小为2.5 mm,注浆泵的转速为500～550 r/min,确保了注浆的效果。可为相关研究提供了一定的借鉴作用。

Construction of new railway lines crossing existing railway lines has become the focus of safety management of the Ministry of Railways. Construction of new tunnels crossing existing railway lines has high safety risks,many restrictive factors and complex engineering environment. Traditional construction methods of Underpass railways require blockade of existing railways. Sample delivery will affect normal railway operation,and then restrict local traffic and economic development. The new pipe curtain method can solve the above problems very well. Through the study of grouting reinforcement technology in triangular area of the new pipe curtain method,the following conclusions are obtained.(1)The survey is accurate,the cutting line of the upper side of the pipe extends from the lower side,and the grouting hole is inside the cutting line to ensure the construction quality of the follow-up work.(2)The drill pipe depth meets the requirements,and the inclination angle of the drill pipe is arranged up and down during the high-pressure rotary grouting. Inconsistent,the top row hole keeps 15~30 degrees up horizontally,the bottom row hole is 30~60 degrees down horizontally,which guarantees the length of the jet grouting pile.(3)When high pressure jet grouting,the rotation angle and speed match the lifting speed,the size of the nozzle is reasonable,the speed of the grouting pump is proportional to the grouting flow,and the appropriate speed of the nozzle and the grouting pump is selected to ensure the grouting pressure,the size of the nozzle is 2.5 mm,and the grouting pump. The rotational speed is 500~550 r/min,which ensures the effect of grouting. It can provide some reference for related research.