During the construction of the subway, there always exist some ubiquitous problems and obstacles every now and then, including variations between the drawing and construction site, underground water temperature and seismic conditions not allowable for wholly scaled exploration and inspection, narrow space for carrying out the construction process, redundant procedures over administration and migration and moving, over harassed by surroundings, all of which attribute the subway construction a toughest one, which can’t be overstated.

However, these problems and toughness can be reduced to the least once precautions or preliminary measures can be taken in time, including the application of scaffolding acrow props.

Shoring devices of different acrow prop specifications plays an important role in the project of constructing the subway, which has been attached with importance by most of the construction entities that are responsible for this kind of building projects. This can be well manifested by the example of China Rainlway 20th Bureau Co. When building the Guiyang Subway, it has taken into consideration the whole circumstances beforehand such as weather, city drainage system, etc. in order to make relevant solutions, including the advanced completion of building acrow props in the 1^st, 2^nd and 3^rd phase, which bestowed a complete assurance to construction process.