侧向辐射注浆技术处治现役高速公路沉降分析

Analysis of settlement of reinforced operating expressway using lateral radiation grouting technique

以连-盐(连云港-盐城)高速公路灌云段为对象,在不影响正常通车的情况下采用侧向辐射注浆技术进行路基加固处理。针对侧向辐射注浆路基加固机制的问题,利用ABAQUS有限元建立数值模型,通过对比有限元计算的注浆加固过程路面隆起、注浆后路面沉降、土体侧向位移和超静孔压与现场试验的测量值,验证了数值模型的可靠性。基于数值模型开展参数分析研究,研究结果表明,侧向辐射注浆技术能够有效地控制现役高速公路的沉降变形,试验路段注浆加固减小沉降达5 cm;注浆率是影响路面隆起量并提高土体压缩模量的主要参数,最终沉降随注浆率增大而线性减小;当注浆土体力学指标较大时注浆加固土体的效果会减弱,但不会对注浆隆起量造成明显影响;对路基的加固时间越早,注浆加固控制沉降的效果就越明显;侧向注浆侧向辐射注浆技术简便,施工过程不影响高速公路正常通车,在控制现役高速公路沉降治理时有较大优势。

To deal with the problem of long-term settlement of the operating expressway, the Guan Yun section of the operating Lianyungang-Yancheng expressway, of which the embankment is improved by the lateral radiation grouting technique, is selected for analysis. A numerical model based on ABAQUS software is established to investigate the reinforcement mechanism of the embankment using the lateral radiation grouting technique. The proposed numerical model is then validated by comparing the calculation results of the ground heave, surface settlement of the ground after grouting, soil lateral displacement and excess pore pressure with the measurement in the field test. Subsequently, parametric study is conducted based on the presented numerical model. The results show that lateral radiation grouting technique can efficiently control the settlement of operating expressway and 5 cm reduction of settlement is achieved in field test section. The increasing of the grouting ratio is the primary factor which leads to the larger ground heave as well as the larger compression modulus of soil; and ultimate settlement decreases linearly with increasing of grouting ratio. Higher soil strength leads to insignificant effect of reinforcement, whereas no significant influence of heave is observed. The effect of grouting is more significant with the time in advance to reinforcing the ground. Thus it can be helpful to the compensation of previous settlement and the control of following settlement. The simple lateral radiation grouting technique has an advantage on reducing operating expressway settlement without influencing the traffic operation.