岩溶区上承式箱型拱桥抗推基础设计研究

王亮，余章亮

摘要:

我国南方多山，地质条件一般较好，跨河桥梁较多的选用了上承式箱型拱桥方案。但是，对于某些区域，地质条件为灰岩，地层中存在一定的岩溶发育，因此对拱桥的设计带来了一定的困难。上承式箱型拱桥水平推力较大，一般采用重力式的扩大基础直接作用在基岩上，如果基岩存在岩溶，基础的稳定性存在一定的风险。如何选择合适的拱桥基础形式，确保结构的安全成为设计师需要研究的关键性问题。本文以某岩溶区上承式箱型拱桥设计为实例，分析了拱脚基础方案的可行性，提出了一种新型的拱桥组合抗推结构，对今后类似工程项目提供了一定的参考价值。

Abstract:

There are many mountains in the south of my country, Geological conditions are generally good. Most cross-river bridge schemes use top-loaded box arch bridges. However, for some areas, the geological conditions are limestone, Karst development exists in the strata. It brings certain difficulties to the design of the arch bridge. There is a large horizontal thrust in the top-loaded box arch bridge, Gravity-type expansion foundations are generally used to directly act on the bedrock. If the bedrock is karst，There are certain risks to the stability of the foundation.Choosing the foundation form of an arch bridge to ensure the safety of the structure has become a key issue for designers to study. This paper takes the design of a box-type arch bridge in a karst area as an example, analyzes the feasibility of the arch foot foundation scheme, and proposes a new type of arch bridge composite thrust structure, which provides a certain reference value for similar projects in the future.