软土地基桥头搭板脱空换填处置技术研究

Research on Treatment Technology of Void Replacement and Filling of Bridge Head Lap Slabs in Soft Soil Foundation

摘要:

我国东南沿海地区软土分布区域广泛，早期在该区域修建的高速公路桥梁桥头搭板下均存在不同程度的脱空病害，考虑到高速公路不能中断交通，通常在桥头搭板上钻孔注浆填充脱空区域，很少采用换填处置方法。结合一个不中断交通的桥头搭板脱空换填处置工程实例，在泡沫混凝土中加入聚丙烯纤维和早强水泥改善其特性，通过合理的台后换填结构设计，在不中断交通的情况下进行换填处置施工，经过3 a运营后，桥头路面通行平顺，锥坡、边坡未出现沉降等病害，说明该加固处置方法效果较好。

Abstract:

In the southeastern coastal region of China, soft soil is widely distributed. In the early days, all the expressway bridges built in this area suffered from varying degrees of voids under the bridge head lap slabs. Considering that traffic on expressways cannot be disrupted, it is common to drill holes and inject grouting on the bridge head lap slabs to fill the voids, and the replacement and filling treatment method is rarely adopted. Combined with an example of a bridge head lap slab void replacement and filling treatment project that does not disrupt traffic, the polypropylene fibers and early-strength cement are added into foam concrete to improve its properties. Through a reasonable design of the backfill structure behind the abutment, the replacement treatment is successfully implemented without interrupting traffic. After 3a operation, the pavement at the bridgehead is smooth for traffic, and no settlement or other diseases have occurred on the cone slope and the slope, which indicates that this reinforcement treatment method is effective.