UHPC预制拼装综合管廊的抗弯性能试验

Performance test of flexural capacity of prefabricated UHPC utility tunnel

针对预制拼装钢筋混凝土(RC)管廊自重大和吊装难的问题,通过试设计超高性能混凝土(UHPC)预制拼装管廊主体构造,并进行1∶2模型的静力试验;得到UHPC综合管廊的顶底板和侧墙在不同荷载作用下的破坏形态、荷载-变形关系、钢筋和混凝土应变,并对整体受力机制、破坏模式和极限承载力进行分析.结果表明,UHPC管廊重量可减少30%,破坏模式与RC管廊基本一致,均为弯曲破坏,但UHPC管廊的开裂荷载和变形能力明显提高.在实测数据的基础上,通过简化拉压区应力分布图形,建立UHPC综合管廊抗弯极限承载力的计算方法,得到的计算值与实测值吻合良好,误差在10%左右.提出的计算公式可为UHPC综合管廊的设计计算提供参考.

Aiming at the problems of self-weighting and hoisting difficulty of prefabricated assembled reinforced concrete(RC)utility tunnel,the main structure of ultra-high performance concrete(UHPC)prefabricated assembled utility tunnel was carried out by trial design,and the static test of 1:2 model was carried out,and the failure form,load-deformation relationship,steel bar and concrete strain of UHPC comprehensive utility tunnel under the action of various levels of load were obtained,and the overall force mechanism,failure mode and ultimate bearing capacity of UHPC comprehensive utility tunnel were analyzed.The results show that the weight of UHPC utility tunnel can be reduced by 30%,and the failure mode is consistent with that of RC utility tunnel,which is bent failure,but the cracking load and deformation ability of UHPC utility tunnel are significantly improved.On the basis of the measured data,by simplifying the stress distribution graph of the tensile pressure zone,the calculation method of UHPC comprehensive utility tunnel bending limit bearing capacity is established,and the calculated value obtained is in good agreement with the measured value,and the error is about 10%.The proposed calculation formula can provide a reference for the design and calculation of UHPC utility tunnel.