【作者】 朱大宇；

【导师】 应惠清；

【作者基本信息】 同济大学 ， 结构工程， 2008， 博士

【摘要】 Glass-Fiber-Reinforced Polymer(玻璃纤维增强聚合物,简称GFRP)筋是由多股连续玻璃纤维采用如聚乙烯树脂、环氧树脂等胶合后,经过特制的模具拉挤成型的。基于GFRP筋的特点,在地下连续墙中盾构穿越区域采用GFRP筋代替钢筋用具有技术和经济上的可行性。这种方法使盾构机进出洞时可以直接切削地下连续墙掘进,简化施工工艺,加快施工进度,减少施工风险,节约投资。然而,目前国内外对于GFRP筋的研究大多集中在永久结构的GFRP筋混凝土构件的工作性能方面,而对GFRP筋地下连续墙的研究,尤其是施工应用研究还相当有限和初步,甚至可以说几乎是一个空白;同时,由于国内外所完成的工程实例相当少,缺乏工程实践积累,还难以提出完整系统的施工方法和工艺。为此,本文以实际工程为背景,采用理论分析、结构试验和现场实测相互结合的方法,在施工应用方面展开了GFRP筋地下连续墙的研究。开发了GFRP筋笼(钢筋笼)的工具式吊装桁架,并进行了预备性试吊的研究,在有限元计算和实测结果的基础上进行了分析。将工具式吊装桁架与传统钢筋加固桁架进行了受力-变形、施工方法以及经济效益方面的比较,证明了工具式吊装桁架在技术和经济上均存在着显著的优势,具有很高的实际应用价值。在预备性试吊的基础上对吊装桁架和吊装过程进行了改进和优化。对利用工具式吊装桁架吊装GFRP筋笼的过程进行了研究,对整个吊装过程进行了有限元建模分析和现场实测,并将有限元分析结果与现场实测数据进行了比较,通过比较得到了一些有价值的结论。对GFRP筋的连接、吊索长度和吊点位置、吊机之间的配合等几个工艺问题进行了探讨。进行了GFRP筋混凝土板和钢筋混凝土板的试验室抗弯试验,对不同配筋率GFRP筋混凝土板进行了有限元模拟试验,描述了试件的受力-变形过程和破坏形态,对两种混凝土板的开裂荷载和极限荷载、挠度以及混凝土的应变进行了对比和分析。同时,探讨了配筋率对GFRP筋混凝土板刚度的影响,给出了GFRP筋混凝土板开裂后抗弯刚度的计算公式。对GFRP筋地下连续墙在开挖及地下结构施工过程中的工作性能进行了有限元建模计算和结果分析,并将有限元计算结果与现场监测数据进行了对比分析,在此基础上进行了影响因素分析,并提出了设计和施工建议。更多还原

【Abstract】 The Glass-Fiber-Reinforced Polymer (GFRP) bar is a kind of material formed with resin and glass fiber compound.Because of the characteristics of GFRP, substituting GFRP bars for steel bars at the soft-eye openings for tunnel shield in diaphragm wall is technically and economically feasible. It allows the shield to cut diaphragm wall directly, consequently simplifies the construction process, speeds up the working progress, reduces risks, and saves the investment. By now, however, both domestic and international studies mainly focus on mechanical properties of concrete members of permenent structures reinforced with GFRP bars and are very poor and elementary on diaphragm wall reinforced with GFRP bars, especially on application in construction practice. In addition, because of lack of domestic and international engineering practice, there is no systematic construction method or process.Based on an engineering practice, a study is carried out on application of diaphragm wall reinforced with GFRP bars by means of theoretical analyses, laboratory tests and field measurements.Portative hoisting truss for GFRP diaphragm wall cage (ordinary steel cage) is devised and used in trial hoisting. A series of analyses is made based on the results of FEM calculations and field measurements. By compared with traditional bracing frame in mechanical properties, construction method and economical efficiency respects, the portative hoisting truss is proved having significant advantages in practice. Through the trial hoisting operation, the hoisting truss and the hoisting process are improved and optimized.The hoisting process of GFRP diaphragm wall cage using portative hoisting truss is studied by means of FEM analyses and field measurements. Some valuable conclusions are made by comparing the data. Several technical problems, such as the connections of GFRP bars, lengths of lifting loops and locations of lifting points, cooperation of cranes, are discussed. Laboratory flexural tests are carried out using concrete slabs reinforced with GFRP bars and steel bars. Concrete slabs with different GFRP reinforcement ratio are tested by FEM simulation. Based on tests results, the deformation process of specimens under load is described. Compares and analyses are made between cracking and ultimate load, deflection and strain of concrete of the two slab types. In addition, effect of GFRP reinforcement ratio to the rigidity of slab is discussed. Prediction equation of flexural rigidity is suggested. This equation is acceptable for concrete slabs reinforced with GFRP bars after cracking.FEM analyses are made towards the service behavior of diaphragm wall reinforced with GFRP bars during the whole process of excavation and construction of inner structures. By comparing the FEM results with the data of field measurements, the Contributory factors are studied. Some suggestions are made towards design and construction.更多还原