It is an acute problem to rebuild these expressways, and digging steps is one of the usual measures.
结合安新高速公路改建工程,分析了旧路开挖施工时可能产生坍塌的原因,提出合适的台阶开挖尺寸,针对不同路基填料尤其是不易松散土(粘土)与易松散土(砂土)提出相应的台阶开挖方案。
The "three bench excavation" is still in developing in our country large stride tunnel construction.
在我国大跨度隧道施工中,“三台阶开挖法”尚处探索阶段,本文结合实际情况,比较“中壁法”和“双侧壁法”,着重介绍了“三台阶开挖法”的开挖工序、支护特点、适用范围、工艺原理、施工组织和经济效益等情况,对于大跨度隧道施工有较高的参考价值。