小俯角旋喷桩处理加固既有路基技术研究

Technology of treating and reinforcing existing roadbed by rotary jet grouting pile with small dip angle

为采用小俯角旋喷桩处理加固既有路基,开展了控制施工关键参数的现场试验研究。结果表明:小俯角旋喷桩桩径随注浆压力的提高而增大,建议小俯角旋喷桩注浆压力控制在20 MPa左右;施工俯角对旋喷桩成桩参数的影响甚微,说明采用该试验的小俯角旋喷施工在技术上合理可行;注浆量随注浆提升速度的提高而连续减少,成桩尺寸也将发生同步变化,综合建议注浆提升速度应控制在25 cm/min以下。

In order to reinforce existing roadbed with small-pitch rotary jet grouting pile,field test was carried out to control key construction parameters.The results show that:the diameter of rotary jet grouting pile increases with the increase of grouting pressure,it is suggested that the grouting pressure of rotary jet grouting pile should be controlled at about 20 MPa.The construction pitch angle has little influence on the pile forming parameters.It shows that it is technically reasonable to adopt the pitch angle value controlled by this test.The grouting volume decreases continuously with the increase of the grouting lifting speed,and the size of piles will change synchronously.It is suggested that the lifting speed should be controlled below 25 cm/min.