The enlarging or reconstruction requirement of existing tunnel, which can be divided into increases based on traffic flow, new ventilation or escape space, old tunnel reinforcement and so on.
既有隧道的扩挖或改建需求，大致可分为基于交通量增加、新增通风或逃生空间、老旧隧道维修补强等。
The enlarging or reconstruction requirement of existing tunnel, which can be divided into increases based on traffic flow, new ventilation or escape space, old tunnel reinforcement and so on.
既有隧道的扩挖或改建需求，大致可分为基于交通量增加、新增通风或逃生空间、老旧隧道维修补强等。
应用推荐