粗合成纤维在排水调蓄盾构法隧洞管片中的应用试验研究  

Test and Study on the Application of Synthetic Macro-fibers in the Segements of Drainage and Storage Tunnels Built by Shield Method

作　　者：官林星 温竹茵 王晓鹏 由广明 孙巍 庄欠伟 GUAN Linxing;WEN Zhuyin;WANG Xiaopeng;YOU Guangming;SUN Wei;ZHUANG Qianwei(Shanghai Municipal Engineering Design Institute(Group)Co.,Ltd.,Shanghai 200092;Shanghai Chengtou Water Group Co.,Ltd.,Shanghai 200002;Shanghai Tunnel Engineering Co.,Ltd.,Shanghai 200032)

机构地区：[1]上海市政工程设计研究总院(集团)有限公司,上海200092 [2]上海城投水务集团有限公司,上海200002 [3]上海隧道工程有限公司,上海200032

出　　处：《现代隧道技术》2022年第6期258-265,共8页Modern Tunnelling Technology

基　　金：上海市科学技术委员会优秀技术带头人计划项目(19XD1432800).

摘　　要：为缓解排水调蓄盾构法隧洞内水压的不利作用,考虑隧洞内部介质为雨污水,提出在隧洞管片中加入粗合成纤维。通过材料力学性能试验、直梁加载试验,研究粗合成纤维在排水调蓄隧洞管片中的应用效果。结果表明,与素混凝土力学参数相比,纤维混凝土的抗压强度、抗折强度、弹性模量分别降低1.8%、7%、4%,纤维的添加会降低混凝土力学性能;在混凝土开裂后,PPF1(粗合成纤维1)、PPF2(粗合成纤维2)、SF(钢纤维)试件的钢筋应力与普通混凝土相比分别下降2%、10%、17%,纤维分担了钢筋的部分拉应力,体现了纤维混凝土的优点;从裂缝的分布形态看,普通钢筋混凝土的裂缝表现为“疏而宽”,试验终止时最大裂缝宽度为0.55 mm,纤维钢筋混凝土的裂缝表现为“密而窄”,试验终止时最大裂缝宽度为0.3 mm。在混凝土开裂后,纤维减小了裂缝的宽度,纤维的加入有利于隧洞衬砌结构的裂缝控制。In order to alleviate the adverse effect of water pressure in the drainage and storage shield tunnel, it is proposed to add synthetic macro-fiber into the tunnel segment considering that the internal medium of the tunnel is rainwater and sewage. Through material mechanical properties and straight beam loading tests, the application effect of synthetic macro-fiber in drainage and storage tunnel segments is studied. The results show that, compared with the mechanical parameters of plain concrete, the compressive strength, flexural strength and elastic modulus of fiber reinforced concrete are reduced by 1.8%, 7% and 4% respectively, and the addition of fiber will reduce the mechanical properties of concrete. After the concrete cracks, the reinforcement stress of PPF1(synthetic macro-fiber 1),PPF2(synthetic macro-fiber 2) and SF(steel fiber) specimens decreases by 2%, 10% and 17% respectively compared with that of ordinary concrete. The fiber shares part of the tensile stress of the reinforcement, reflecting the advantages of fiber reinforced concrete. From the distribution pattern, the cracks of ordinary reinforced concrete are "sparse and wide", and the maximum crack width at the end of the test is 0.55 mm;the cracks of synthetic fiber reinforced concrete are "dense and narrow", and the maximum crack width at the end of the test is 0.3 mm. After the concrete cracks, the fiber reduces the width of the crack, and the addition of fiber is beneficial to the crack control of the tunnel lining structure.

关 键 词：盾构隧道 管片 纤维混凝土 裂缝 

分 类 号：U451.5[建筑科学—桥梁与隧道工程]