某盾构区间下穿某河及采砂坑原因分析与处理措施

Cause Analysis and Treatment Measures of a Shield Section Crossing a River and Sand Pit

某盾构区间左线第一次下穿某河期间,施工单位安全风险意识较为淡薄,未充分做好应急预案及物资储备,河底出现渗漏。后续三次穿越某河期间,施工单位做好应急预案及物资储备,穿越期间未出现异常情况。盾构右线穿越采砂坑期间,采砂坑区域地面出现明显下沉,且地面出现纵向裂缝。由于穿越期间同步注浆量偏低,且盾尾刷损坏未及时修复。通过盾尾底部填充海绵、钢丝球等措施,有效控制盾尾漏浆情况,同时保证同步注浆质量,变形得到有效控制。

During the first time that the left line of a shield section crosses a river,the construction unit's safety risk awareness is relatively weak,the emergency plan and material reserve are not fully prepared,and the river bottom leaks.During the following three times of crossing a river,the construction unit made emergency plans and material reserves,and there were no abnormalities during the crossing.When the right line of shield passes through the sand pit,the ground in the sand pit area sinks obviously,and longitudinal cracks appear on the ground.Due to the low amount of synchronous grouting during crossing and the damage of shield tail brush,it was not repaired in time.By filling sponge and steel wire ball at the bottom of shield tail,the slurry leakage of shield tail can be effectively controlled,the synchronous grouting quality can be guaranteed,and the deformation can be effectively controlled.