摘要
高强钢筋具有强度高、延性好、强屈比高、应变时效敏感性低、焊接性能及冷弯性能良好等诸多优点,工程应用前景良好。按照高速铁路隧道Ⅳa围岩标准断面,分别采用普通钢筋和高强钢筋浇筑3组格栅混凝土复合支护构件,通过室内加载试验对3组构件的力学特性、隧道工程适用性和复合支护特性进行研究,得到以下结论:1高强构件极限荷载及相应的跨中挠度、二次加载极限荷载和最大回弹位移均大于普通构件,表明高强钢筋的应用能够显著改善复合支护结构的力学性能;2在地质条件较好的隧道工程中,高强支护结构的应用有利于降低工程造价、提高工程质量和支护结构安全性;相反,在普通支护结构难以进行有效支护的软弱围岩隧道工程中,具有高强度和大变形特性的高强支护结构有利于解决隧道大变形的问题;3高强支护结构和普通支护结构的荷载-挠度曲线变化趋势一致,因此,提出一种以荷载-挠度关系表征的格栅混凝土复合支护特性曲线,并通过对比分析Oreste假设的复合支护特性曲线的诸多不足之处。
High-strength reinforcement, which is characterized by many advantages such as high strength, good ductility, high tensile-to-yielding strength ratio, low sensibility of strain aging and good performance of welding and cold bending, has quite good application prospects in practical engineering. In this study, according to the standard cross- section of IV a-level surrounding rock of the high-speed railway tunnel, 3 groups of composite support members were made of high-strength steels and conventional steels, respectively. Based on laboratory tests, the mechanical characteristics, applicability of tunnel engineering and characteristics of three groups of composite supports were studied, and the results can be summarized as follows： （1） Compared to the common members, composite supports made of high- strength reinforcement have higher ultimate load, larger mid-span deflection, higher ultimate load at secondary loading and larger value for the maximum resilient displacement, indicating that the application of high-strength reinforcement can dramatically improve the mechanical characteristics of the composite supports; （2） For the tunnel engineering with good geological conditions, the application of high-strength supports is advantageous in reducing the construction cost and improving the construction quality and the safety of the supports. On the contrary, the conventional supports are usually not effective for poor geological conditions, while the high-strength supports, which are characterized by the functional properties of high-strength and large deformation, is beneficial to solving the problem ; （3） The development trend of load- deflection curves of the high-strength supports and the conventional supports is consistent, so a new composite support characteristic curve is proposed. Compared to the new curve, some disavantages associated with the support characteristic curve assumed by Oreste are introduced.
出处
《土木工程学报》
EI
CSCD
北大核心
2015年第9期104-111,共8页
China Civil Engineering Journal
基金
国家自然科学基金重点项目(U1234210
51134001)
关键词
高强钢筋
力学特性
适用性
复合支护特性
室内试验
high-strength reinforcement
mechanical characteristics
applicability
composite support characteristics
laboratory test
作者简介
于富才（1985-），男，博士研究生。主要从事隧道和地下工程的研究。
张顶立（1963-），男，博士，教授。主要从事隧道和地下工程的研究。
房倩（1983-），男，博士，副教授。主要从事隧道和地下工程的研究。
台启民（1987-），男，博士研究生。主要从事隧道和地下工程的研究。
孙毅（1987-），男，博士研究生。主要从事隧道和地下工程的研究。
