When the bore hole-top-enclosed grouting method is used to conduct high-pressure curtain grouting, shallow weathered broken rock is easy to be split, resulting in excessive grout loss.

• 采用孔口封闭灌浆法进行高压帷幕灌浆时,对于浅层风化破碎岩体易产生多次劈裂而流失过多浆液造成浪费。