成昆线多数长隧道采用中心水沟钢筋混凝土支承块式整体道床。由于各种原因,遣床或承轨槽产生纵横向裂缝,使支承块松动与道床脱离(图1),或者造成支承块挡肩破损(图2)。我们承担成昆线银丝岩隧道病害整治工程中就有成千块这样松动和挡肩破损的支承块。设计文件要求打眼放炮凿除更换支承块。这种处理办法,由于放炮而将未松动支承块震松造成新 Most of the long tunnels of Cheng-Kun line adopt the central ditch reinforced concrete support block-type integral track bed. Due to various reasons, there are vertical and horizontal cracks in the bed or track groove, causing the support block to loosen and detach from the bed (Figure 1), or causing the support block to be damaged (Figure 2). We assume Cheng Kun line siltyite tunnel disease remediation project there are thousands of pieces so loose and block shoulder block damage. Design documents require drilling shot blasting in addition to replace the support block. This approach, due to blasting loose loose bearing blocks will cause new pine