Research And Application On Hydraulic Drive Technology Of Pipe Jacking Machine In Mix Ground

With the growth of population and the rapid development of economy,people's use of underground space more and more,The comprehensive pipelines such as sewage,gas,petroleum,thermal and communication cables are usually buried directly underground and intricate.However,the early old pipes due to the lack of unified planning,and many pipelines have been seriously aging,they have been unable to meet the needs of the construction of city and urban development.For this reason,the country has issued a series of policies to control the underground comprehensive pipe gallery,not only for the transformation of underground pipelines,but also for underground garages and shopping malls.In municipal construction,the pipe jacking machine become an indispensable tunneling equipment,especially with the development of the city,the common trench needs will be more intense,It is expected that in the next ten years,the market demand for pipe jacking machines will be very strong,and it is widely used in underground pipeline construction,such as rivers,roads,buildings and other conditions,with good market prospects.At present,the jacking machine in the domestic market only adapts to the soft soil layer rich in silt,sand,clay,silt,etc.,but there are few application cases in the composite stratum where soft rock and hard rock alternate.In addition,the driving mode of the motor driven cutter of the conventional pipe jacking machine works in the condition of such a composite stratum,and the over-torque,clamping cutter are often found.Therefore,it is necessary to find a type of driving mode that can adapt to the composite stratum to replace the driving mode of the motor.In order to solve the above problems,studying and analyzing the driving mode of tunneling in hard rock TBM and the jacking machines cutter head,design a set of cutterhead center drive variable motor-variable pump closed hydraulic system.The hydraulically driven cutterhead is more suitable for hard rock and composite ground,According to the geological conditions and design the three modes of jam releasing,low speed and high speed,increasing the scope of construction pipe jacking machine for rock formation,with theoretical calculation,the relevant parameters of the variable motor-variable pump coupled,The whole hydraulic system is simulated by the AMESim simulation software,and relevant parameters are optimized for the weak links in the system to better adapt to the working conditions.Through the situation of practical application proved that the closed hydraulic system instead of motor drive mode completely satisfies the requirement of the excavation of composite ground.