Experimental Research On Force Performance Of Precast Concrete Underground Comprehensive Municipal Tunnel

Precast concrete has become the main construction method of urban underground comprehensive municipal tunnel.The assembling method submitted by Harbin Institute of Technology is a new construction methods tha t Wall and plate which are in the form of prefabricated laminated are producted in the factory,transported to the site to be assembled and casted.The technology is based on the theory of precast concrete structural system which is independently developed by Harbin Institute of Technology as the core of "reinforced steel plug ring technology" and "Restraint lap steel technology". Currently, the laminated plate assembly comprehensive municipal tunnel has been initially used in the construction of Harbin city.Its main advantage is that by means of industrial production,it improves the production efficiency, transport efficiency, the installation efficiency, and construction efficiency,and avoid the drawbacks of traditional construction.In this paper, the main experimental research is for the steel connection and the tunnel nodes form.Specific contents are as follows:In order to study different ways of reinforcement, different axillary foot height,different tunnel nodes positions affected mechanical properties of the tunnel.We designed a total of seven kinds of tunnel node in this experiment.Through the experiment, obtained the crack development situation under monotonic static load,and an objective summary and analysis of the damage phenomenon is made. We obtain the load displacement curve, the strain development curve of steel bar and concrete, the deflection curve and the ductility of the component.On the basis of the experimental data, the serviceability limit state and limit state of bearing capacity of the component are analyzed and compared.Analysis results show that,the mechanical properties of the laminated plate assembly specimen and the cast specimen are basically the same.The overall performance of the assembly is good.In order to simulate the stress condition of the actual tunnel, we designed a full scale test of the laminated assembly type tunnel with two warehouses.Through the measurement of the performance of the strain, displacement, crack and water resistance of the tunnel.We comprehensively evaluate the performance of the tunnel.On the basis of the experiment of nodes,the theoretical analysis of the "inner arch effect" of the whole tunnel under biaxial load is carried out.The calculation method of bearing capacity is given.On the basis of a large number of test results, this paper had made ABAQUS finite element comparative analysis. and got the load- displacement curves and the stress cloud of reinforced and concrete. The results showed that the experimental and simulated values fit highly consistent,and had given to provide a reference for finite element modeling method.