Experimental Study and Performance Comparison of Different Jacking Pipes under the Effects of Concentrated Loads

Pipe jacking is one of the trenchless methods that can satisfy the majority needs of municipal pipeline construction and can be widely used all over the world. However, the construction scenarios and engineering geological environments are becoming more complex, especially jacking through the gravel or pebble stratum condition. The impacts of concentrated loads from the gravel or pebbles on the jacking pipes have not been well examined. This paper designed a concentrated load-bearing test for jacking pipes to simulate the effects under the action of pebbles or cobblestones. This study tested and compared the performance of reinforced concrete, fiber-reinforced concrete, and steel shell–reinforced concrete pipes under concentrated loads to improve their load-bearing capacity in challenging conditions. Moreover, a comparative study was conducted on the aforementioned three pipes under a concentrated load. According to the test data, pipes are more susceptible to damage under concentrated loads. The load-bearing capacity of the steel shell–reinforced concrete pipe was 39.88% and 12.77% higher than that of reinforced concrete pipe and fiber-reinforced concrete pipe, respectively. In terms of deformation ability, the fiber-reinforced concrete pipe displayed 91.55% and 39.34% higher ability than that of steel shell–reinforced concrete pipe and reinforced concrete pipe, respectively. The findings of this research have intuitive reference value for the subsequent design of pipe jacking in gravel and pebble formations.