软弱围岩隧道钢纤维混凝土衬砌承载特性模型试验研究

发布时间：2019-03-03 09:31

【摘要】：为满足软弱围岩隧道开挖后尽快封闭岩面、适应一定变形及提供足够支护力的要求,通过素混凝土、钢筋混凝土及钢纤维混凝土衬砌力学行为室内模型试验,对钢纤维混凝土衬砌的承载特性进行研究。研究结果表明:钢纤维混凝土衬砌初裂荷载提高了20%,极限荷载得到较大提高;掺入钢纤维后衬砌结构韧性增强,初裂后仍能抵抗一定变形并较大降低变形速率,与素混凝土、钢筋混凝土相比可承受更大的变形;钢纤维混凝土衬砌初裂后承载特性曲线缓慢上升,至2倍初裂荷载时仍无收敛迹象,素混凝土快速收敛,钢筋混凝土在一定缓慢上升后快速趋于收敛,软弱围岩条件下,钢纤维混凝土初支在一定变形后可与围岩特征曲线相交,达到围岩结构稳定状态,是一种力学性能良好的快速支护材料。研究成果对软弱围岩隧道的设计与施工都具有重要的意义。
[Abstract]:In order to meet the requirements of sealing rock surface as soon as possible after excavation of soft surrounding rock tunnel, adapting to certain deformation and providing sufficient support force, the mechanical behavior of plain concrete, reinforced concrete and steel fiber reinforced concrete lining was tested in laboratory. The bearing capacity of steel fiber reinforced concrete (SFRC) lining is studied. The results show that the initial crack load of steel fiber reinforced concrete (SFRC) lining is increased by 20%, and the ultimate load is greatly improved. With the addition of steel fiber, the toughness of the lining structure is enhanced, and after the initial crack, the lining can resist certain deformation and greatly reduce the deformation rate. Compared with plain concrete and reinforced concrete, the reinforced concrete can bear more deformation. After the initial crack, the load-bearing characteristic curve of the steel fiber reinforced concrete lining increases slowly, and there is still no evidence of convergence when the initial crack load is 2 times. The plain concrete converges rapidly, and the reinforced concrete tends to converge rapidly after a certain slow rise, under the condition of weak surrounding rock. The initial support of steel fiber reinforced concrete (SFRC) can meet the characteristic curve of surrounding rock after a certain deformation, which can reach the stable state of surrounding rock structure. It is a fast supporting material with good mechanical properties. The research results are of great significance to the design and construction of soft surrounding rock tunnel.
【作者单位】：北方工业大学土木工程学院;石家庄铁道大学土木工程学院;河北交通职业技术学院土木工程系;中铁七局集团郑州工程有限公司;四川省交通厅公路规划勘察设计研究院;
【基金】：国家自然科学基金项目(51408008,51478277) 国家十二五科技支撑项目(2012BAK09B06) 河北省自然科学基金项目(E201619002) 四川省应用基础研究计划项目(2014JY0090,2015JY0166) 北京市教委青年拔尖人才培育计划项目北方工业大学科研创新团队(XN018007)
【分类号】：U451.5

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