单层衬砌聚烯烃粗纤维喷射混凝土性能试验及工程应用

Performance Test and Engineering Application of Macro-polyolefin Fiber Reinforced Shotcrete Used as Single-shell Lining

为了研究聚烯烃粗纤维混凝土喷层在隧道单层永久衬砌支护中的适用性,根据合成纤维喷射混凝土结构力学原理,首先对聚烯烃粗纤维在混凝土中的增强力学作用机理进行了分析,然后对聚烯烃粗纤维喷射混凝土的力学性能及耐久性进行了室内试验,并依托青岛地铁西镇车站工程实例,对其拱顶下沉、水平收敛、地表沉降监控量测结果进行了分析,同时采用FLAC3D数值计算软件进行分析,结果表明,聚烯烃粗纤维喷射混凝土抗压、抗拉强度高,韧性好,耐久性优良,现场喷射作业回弹率小,是一种理想的单层永久衬砌支护材料,具有较好的推广应用价值。

In order to study the applicability of the macro-polyolefin fiber reinforced shotcrete layer to permanent single-shell lining in tunnels,the mechanical mechanism of the macro-polyolefin fiber reinforcement in concrete is firstly analyzed based on the mechanics principle of synthetic fiber shotcrete structure,and then the mechanical property and durability of macro-polyolefin fiber reinforced shotcrete is tested in the laboratory.Besides,the moni⁃toring and measurement results of the crown settlement,horizontal convergence and the ground surface settlement are analyzed based on the project case of Xizhen Station of Qingdao Metro,and the three dimensional numerical analysis is also conducted by the FLAC3D.The results show that the macro-polyolefin fiber reinforced shotcrete has a high compressive and tensile strength,good toughness and excellent durability,low rebound rate in spraying opera⁃tion during the field implementation process.Therefore,it is an ideal support material for the permanent singleshell lining with good application value.