Experimental complex for research of the soil thrust process with correction of boring trajectory

Abstract. Lately soil thrust boring technique has been widely used for construction of the service lines in urban areas all over the world. The deflection of the trajectory of the working body from the designed one is one of the disadvantages of the traditional technique of soil thrust boring by the conic working body, especially in the soil with a different density. Thus, the research of the ways to improve the accuracy of the soil thrust boring is a topical issue. A review of the researches and technical solutions allows to find out the trends in development of trenchless technique of service lines by soil thrust boring with correction of the trajectory. The idea of correction of soil thrust boring trajectory and structures of the plants for implementation of this method have been received. The steerable soil thrust boring by horizontal directional drilling is a difficult and expensive process, which is effective for curve trajectories and long boring distances over 100 m. For relatively short distances (from 15-20 to 100 m) a rectilinear trajectory is required. It is difficult to obtain such condition for a number of reasons; it was proposed to research the possibility of the correction of trajectory by using quite a simple plant for implementation the translation motion and in some cases to provide the rotation motion in order to change the position of the slanted soil thrust head by the specific hydro cylinder with built-in screw gage. The aim of the research is to justify scientifically the parameters and features of the soil thrust boring equipment with active correction of the boring trajectory, which were received from experimental data using the equipment for implementation of the research process in natural soil condition. Conclusion. According to the results of the tests which were carried out at the test site of “NPP “Gaztehnika” the operability and unique design of the power plant, which allows to create translation motion of the connecting rods and in some cases to provide the rotation of the connecting rods and soil thrust head were confirmed. Using the experimental plant it was found out that the soil thrust boring by rotating conical working body is 1.5…2 times less than by the static soil thrust boring.