盾构隧道衬砌结构环向连接螺栓作用机制研究——以上海地铁为例
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摘要
地铁隧道管片螺栓由于遭受地下水中腐蚀性介质侵蚀而导致管片结构耐久性受影响的问题显得特别突出,直接关系到地铁管片结构的正常安全运行和使用年限。在管片设计时连接螺栓有利于提高管片接头的连接刚度、增强结构的整体性和控制结构的变形,但对于连接螺栓在管片结构受力过程中的作用机制仍不明。文章开展了考虑环向连接螺栓锈蚀和失效两种情况下盾构隧道衬砌结构力学性能的顶部超载工况足尺试验研究,并与已开展的环向连接螺栓完好的整环结构足尺试验结果进行对比,揭示了环向连接螺栓的作用机制。整环试验的结果表明:结构受力过程分为三个阶段,分别为弹性阶段、弹塑性阶段和塑性阶段;弹性阶段中,环向连接螺栓劣化对于结构的受力性能影响有限;弹塑性阶段中,环向螺栓弹性模量降低导致结构整体刚度大幅降低;塑性阶段中,环向螺栓劣化导致结构极限承载力降低。
In the damp environment where groundwater flows through, tunnel segments are corroded by various corrosive medium existing in the groundwater. The durability problem of segmental linings is especially prominent due to the corrosion damage of the circumferential joint bolts,which directly concerns the operation safety and the service life of segmental structures. It is generally considered that bolts can increase the stiffness of segment joints,which can improve the integrity and control the deformation of the structure. But the mechanism of the circumferential joint bolts is still unknown. Full-scale tests are conducted on the mechanical capacity of shield tunnel lining structures with corroded circumferential joint bolts and uncorroded circumferential joint bolts. With comparison to the results of full-scale test of the overall structure with bolts in good condition, the mechanism of the circumferential joint bolts is revealed. According to the results of the full-scale test, we can draw the following conclusions : the full mechanical process of the structure can be divided into three stages : the elastic stage, the elastic-plastic stage and the plastic stage. In elastic stage,the deterioration of the circumferential joint bolts has limit influence on the mechanical property of the structure. In elastic-plastic stage, with the reduction of the circumferential joint bolts' modulus of elasticity, the overall structural stiffness decreases. In plastic stage, the ultimate bearing capacity of the structure decreases due to the deterioration of the circumferential joint bolts.
In the damp environment where groundwater flows through, tunnel segments are corroded by various corrosive medium existing in the groundwater. The durability problem of segmental linings is especially prominent due to the corrosion damage of the circumferential joint bolts,which directly concerns the operation safety and the service life of segmental structures. It is generally considered that bolts can increase the stiffness of segment joints,which can improve the integrity and control the deformation of the structure. But the mechanism of the circumferential joint bolts is still unknown. Full-scale tests are conducted on the mechanical capacity of shield tunnel lining structures with corroded circumferential joint bolts and uncorroded circumferential joint bolts. With comparison to the results of full-scale test of the overall structure with bolts in good condition, the mechanism of the circumferential joint bolts is revealed. According to the results of the full-scale test, we can draw the following conclusions : the full mechanical process of the structure can be divided into three stages : the elastic stage, the elastic-plastic stage and the plastic stage. In elastic stage,the deterioration of the circumferential joint bolts has limit influence on the mechanical property of the structure. In elastic-plastic stage, with the reduction of the circumferential joint bolts' modulus of elasticity, the overall structural stiffness decreases. In plastic stage, the ultimate bearing capacity of the structure decreases due to the deterioration of the circumferential joint bolts.
引文
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[2]孙钧.崇明长江隧道盾构管片衬砌结构的耐久性设计[J].建筑科学与工程学报,2008,25(1):1-9.SUN Jun. Durability Design of Shield Lining Structure of Chongming Yangtze River Tunnel[J]. Journal of Architecture and Civil Engineering,2008,25(1):1-9.
[3]袁勇,刘涛,柳献.运营越江隧道服役现状调查与检测评估[J].东南大学学报(自然科学版),2006,(S2):83-89.YUAN Yong,LIU Tao,LIU Xian. Investigation and Evaluation of Operation Status of Operation of Cross-river Tunnels[J]. Journal of Southeast University(Natural Science Edition),2006,(S2):83-89.
[4]黄宏伟,严佳梁,徐凌.软土盾构隧道管片环接头的形式及其设计建议[J].地质与勘查,2003,39(S2):17-22.HUANG Hongwei, Y AN Jialiang,XU Ling. Forms and Design Suggestions of Segment Ring Joints for Shield Tunnels in Soft Soils[J]. Geology and Prospecti ng, 2003,39(S2):17-22.
[5]孙钧.崇明长江隧道盾构管片衬砌结构的耐久性设计[J].建筑科学与工程学报,2008,25(1):1-9.SUN Jun. Durability Design of Shield Lining Structure of Chongming Yangtze River Tunnel[J]. Journal of Architecture and Civil Engineering,2008,25(1):1一9.
[6]刘涛.既有盾构隧道结构性能评价研究[D].上海:同济大学,2008.LIU Tao. Research on Structural Performance Evaluation of Existing Shield Tunnel[D]. Shanghai:Tongji University,2008.
[7]毕湘利,柳献,王秀志,等.通缝拼装盾构隧道结构极限承载力的足尺试验研究[J].土木工程学报,2014,47(10):117-127.BI Xiangli, LIU Xian, WANG Xiuzhi,et al. Full-scale Experimental Study on Ultimate Bearing Capacity of Shielded Tunnel Structures with Joints[J]. China Civil Engineering Journal,2014,47(10):117-127.
[8]柳献,张浩立,鲁亮,等.超载工况下盾构隧道结构承载能力的试验研究[J].地下工程与隧道,2013,18(4):10-15.LIU Xian,ZHANG Haoli,LU Liang,et al. Experimental Study on Bearing Capacity of Shield Tunnel under Overload Conditions[J]. Underground Engineering and Tunnel,2013,18(4):10-15.