玻璃纤维筋在地铁围护桩设计中的研究及应用

摘要

The glass fiber reinforced plastics (GFRP) have been widely used in retaining pile of end soil of shield metro;but the study of the bearing capacity of circular cross-section of GFRP reinforced concrete components is insufficient.As a result,the calculation formula of the cross-section bearing capacity of the rounded GFRP reinforced concrete flexural components based on concrete compressive failure is deduced.And then it is compared with the calculation formula of the existing industry standard,Technical Specification for Shield-cuttable Concrete Reinforcement,in terms of the reinforced bar and safety reservation.The results show that,compared to the existing industry standard,the calculation formula deduced is superior to that from the existing industry standard in terms of reinforced bar design and construction cost under the conditions of diameter of component less than 1 m and design bearing capacity less than 1 000 kN · m;and after further study,the calculation formula deduced shows much more advantageous in terms of reinforced bar control and construction cost under the condition of diameter of component larger than 1 m.%为解决当前地铁建设中玻璃纤维筋在盾构端头围护桩中大量应用而相应圆形截面玻璃纤维筋混凝土构件设计计算等研究不足这一矛盾,通过公式推导得到基于混凝土受压破坏的圆形玻璃纤维筋混凝土受弯构件的正截面承载力计算公式,并与现有行业标准《盾构可切削混凝土配筋技术规程》中关于圆形玻璃纤维筋混凝土受弯构件正截面承载力计算公式进行对比,从配筋及安全储备等角度进行分析.结果表明:相比《盾构可切削混凝土配筋技术规程》中关于玻璃纤维筋圆形混凝土构件正截面承载力的计算公式,本文所推导基于混凝土受压的玻璃纤维筋混凝土圆形截面构件计算公式在直径不大于1 m、设计承载弯矩小于1 000kN·m时,配筋量设计更为优化,有利于控制造价,进一步研究发现当直径大于1 m时,本文所推导公式在减少配筋、控制造价上更有优势.