超高车辆-预应力混凝土箱梁桥碰撞荷载分析及撞后承载力评估  

Analysis on Collision Load of Over-height Vehicle on PC Box Girder Bridge and Residual Bearing Capacity Evaluation

作　　者：邹育麟 邹品德 申鹏 张景峰 ZOU Yu-lin;ZOU Pin-de;SHEN Peng;ZHANG Jing-feng(Sichuan Yanjiang Panzhihua-Ningnan Expressway Co.,Ltd.,Panzhihua Sichuan 617112,China;Bridge Engineering Co.,Ltd.of Sichuan Road&Bridge Construction Group,Chengdu Sichuan 610017,China;Sichuan Transportation Construction Croup Co.,Ltd.,Chengdu Sichuan 610041,China;School of Highway,Chang'an University,Xi'an Shaanxi 710064,China)

机构地区：[1]四川沿江攀宁高速公路有限公司,四川攀枝花617112 [2]四川路桥桥梁工程有限责任公司,四川成都610017 [3]四川省交通建设集团股份有限公司,四川成都610041 [4]长安大学公路学院,陕西西安710064

出　　处：《公路交通科技》2022年第3期91-99,132,共10页Journal of Highway and Transportation Research and Development

基　　金：国家自然科学基金项目(51808048);四川省交通运输科技项目(2018-ZL-04)。

摘　　要：为研究超高车辆-预应力混凝土箱梁桥碰撞荷载及撞后结构的承载性能劣化规律,建立了精细的超高车辆撞击预应力箱梁桥有限元模型,并验证了数值计算模型的准确性和可靠性。分别考虑车辆速度、载重量、超高高度、车厢刚度、撞击角度以及混凝土强度等6个因素,采用显式动力分析软件LS-DYNA进行不同参数下(18个工况)超高车辆-桥梁上部结构碰撞分析。结果表明:碰撞力时程曲线可以简化为突变阶段、振荡阶段以及衰减阶段3个不同阶段;碰撞过程中的冲量主要受碰撞力峰值、碰撞力均值和均值力持时影响,不同计算参数对简化碰撞力关键指标的影响有较大差异;碰撞过程中,车辆动能主要转化为车辆的塑性变形应变能;不同撞击工况下,被撞梁的竖向极限承载力下降水平都在18%以内;当预应力钢束撞断失效退出工作情况下,主梁的工作性能会受到严重影响,被撞侧底板及腹板钢束同时失效时,结构的竖向极限承载力下降程度达到54%。因此,需要对预应力钢筋的设计和防护予以重视。研究结果可以为建立简化碰撞力计算模型提供依据,并为桥梁防撞设计提供参考。In order to study the collision load of the over-height vehicle on the PC box girder bridge and the degradation of residual load bearing performance of the collided structure, a high-resolution FE model of the PC box girder bridge collided by ultra-high vehicle is established, and its accuracy and feasibility is verified. Considering the vehicle velocity, load capacity, over height, carriage stiffness, collision angles and concrete strength respectively, the situations of collision between over-height vehicle and bridge superstructure with different parameters(18 working condition) are analyzed by using explicit dynamic analysis software LS-DYNA. The result shows that(1) The collision force time-history curve can be simplified into mutation stage, oscillation stage and decay stage.(2)The impulse during collision is mainly affected by the peak value, mean value and duration of collision force, the influence of different calculation parameters on the key indicators of the simplified collision force is different.(3) Most of vehicle kinematic energy converted into plastic strain energy of the vehicle during collision.(4)The vertical ultimate bearing capacity of collided girder decreased within 18% under various cases.(5) The performance of main girder degraded severely as the prestressed tendon failed due to collision load, and the structural vertical ultimate bearing capacity decreased by 54% if the tendons in the bottom slab and web of collided side both failed. Therefore, attention should be paid to the design and protection of prestressed tendons. The research result can provide a basis for establishing simplified collision force model and a reference for bridge anti-collision design.

关 键 词：桥梁工程 碰撞荷载 数值模拟 承载力评估 超高车辆 预应力混凝土箱梁桥 

分 类 号：U447[建筑科学—桥梁与隧道工程]