Experimental Study On New Structure Of Single-layer Freezing Shaft Linings

The current freeze shaft lining mainly used double-reinforced concrete composite shaft lining structure. This shaft lining structure has been widely used in our country, but it has its own drawbacks:large of shaft lining thickness, high cost of the construction process, complicated of the construction process, long construction period and ect. Compared single-layer freeze shaft lining with double-layer shaft lining and composite shaft lining, the advantages of it shaft lining thickness is small, the construction process is simple, it cost relatively low, its relatively short duration and etc. However, there are disadvantages of single-layer shaft lining, such as there are many joint parts during the short segment excavation construction process, the shaft lining jiont parts shrinkage formation cracks are easier infiltration (leaking) water. To resolve the challenge of single-layer shaft lining infiltration (leaking) water, this paper,based on the depth understanding of the status of the freeze shaft lining, combining theoretical analysis and experimental methods to study the sigle-layer wall's jiont part of water jiont systematically.Firstly, from the design theory for the shaft lining and forces were described, in considering the shaft lining concrete under the action of pore water seepage, using elastoplastic damage mechanical under Fluid-solid coupling interaction derived concrete shaft lining stress distribution and the theory of limit stress resistance. Secondly, the outer shaft lining joint were analyzed, proposed three proposals of using micro- expansion of fiber reinforced concrete material, double-conical shaft lining connector and adding steel waterproof connector,then analysis and explanation the three proposals theoretically. Finally, studying the use of micro- expansion of fiber concrete material and the double-conical wall combination proposal compared with the combination proposal of the micro- expansion of fiber reinforced concrete and steel waterproof connector. The results show that,the structural waterproofing effect of the double-conical with micro-expansion of fiber concrete shaft lining is better. Although the steel waterproof connector with micro-expansion of fiber concrete shaft lining emerge some seepage phenomenon,its still has some viability.