钢筋混凝土空心薄壁高墩爆破拆除数值模拟

Numerical Simulation of Explosive Demolition of High Hollow Thin-wall Reinforced Concrete Piers

在桥梁结构中,钢筋混凝土薄壁高墩常因其自身的稳定失效问题而需要被拆除。高为50 m的垂直度不满足要求的钢筋混凝土薄壁高墩,根据现场作业环境,决定对其实施定向爆破拆除。利用有限元分析软件ANSYS/LS-DYNA,建立了薄壁高墩的分离式共节点模型;采用两种模拟方案对薄壁高墩进行数值模拟研究分析,两方案中的爆破切口形状分别为正梯形和倒梯形,并且对其倒塌效果和倒塌范围进行了对比;结合现场实际需求和数值模拟效果,选取倒梯形的爆破切口对薄壁高墩实施爆破拆除,达到了预期的爆破效果。结果表明:分离式共节点模型可以模拟薄壁高墩的倒塌过程,并且倒梯形切口更有利于薄壁高墩的定向爆破拆除倒塌。

The high thin-wall reinforced concrete piers in bridge structure were often demolished by explosive blasting due to the stability failure problems. A 50 m high thin-wall reinforced concrete pier was designed to be demolished directionally by blasting according to the surroundings. Firstly, a common node of separate model of the high thin-wall reinforced concrete pier was built with finite element software ANSYS/LS-DYNA;then, the high thin-wall pier was analyzed with two numerical simulation schemes. The blasting cut was separately trapezoidal and inverted trapezoidal, and the collapse effect and the scope of collapse were compared; finally, the inverted trapezoidal blasting cut was applied to the blasting demolition process combining with the requirement and numerical simulation result, and the expected effect was obtained. The results show that the separate common node model simulated the collapse process of high thin-wall piers well and the inverted trapezoidal blasting cut was apt for thin-wall high piers demolition with directional blasting.