预切槽法是隧道暗挖施工的一种超前支护工法,此工法可大幅度降低地表沉降量,对隧道围岩土体及地表建(构)筑物影响较小.采用室内试验和数值模拟的方法,针对浇筑预切槽管片所用混凝土的前期强度、合理支护时机以及预切槽管片接头处合理的接茬方式进行了研究.研究结果表明,按C30 配比的混凝土养护 1.5～2 h时即具有 6 MPa以上的抗压强度,满足拆模要求;粘接介质对管片环向位移的约束效果明显,环氧树脂可作为优良的管片粘接剂;榫槽式接头榫头角度α的理想范围为 55°～70°,综合考虑预切槽工艺的可操作性,榫槽式接头深度B的理想范围为 6～8 cm.
Abstract
Pre-grooving method is a kind of over-advance support method for tunnel excavation,which can greatly reduce the amount of surface settlement,and has less impact on the tunnel surrounding rock and soil and surface buildings(structures).Using in-door tests and numerical simulation methods,the research was carried out on the strength of the concrete used for casting pre-grooving duct piece,the reasonable support timing,and the reasonable stubbing method at the joints of the pre-grooving duct piece.The results show that the concrete with C30 proportion has a compressive strength of more than 6 MPa when curing for 1.5～2 h,which meets the requirement of mold removal;the bonding medium has obvious restraining effect on the circumferential displacement of the duct piece,and epoxy resin can be used as an excellent bonding agent for the duct piece;the ideal range of mortise and tenon joint mortise angle α is 55°～70°,and the ideal range of the depth of the mortise and tenon joint is 6～8 cm,taking into consideration of the operability of the pre-grooving process.
维普
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