An Online Quality Remote Monitoring System Of CFG Pile Construction

In recent years,with the continuous improvement of the country’s infrastructure,the construction of high-speed railways has developed rapidly.Due to the high bearing capacity and good stability of the Cement Fly-ash Gravel Pile(CFG Pile)composite foundation,it has an increasing proportion in the reinforcement of soft soil subgrades for railway construction.During CFG pile construction,each rig needs to be equipped with 3-5 field personnel to verify and record CFG pile construction parameter information.The construction management efficiency is low and the personnel utilization rate is not high.It is difficult to guarantee the real-time and authenticity of the construction parameter information.Therefore,it is necessary to combine the sensor technology,wireless communication technology and Internet technology to study the CFG pile digital construction and monitoring technology.It is of great significance to improve the construction quality of CFG piles and reduce the number of construction personnel on site.Firstly,based on the CFG pile construction process and the working principle of the construction equipment,carried out the CFG pile construction monitoring demand analysis and management demand analysis.then,determined the main monitoring parameters such as the position of pile formation,pile formation depth,pipe sinking speed,pipe pulling speed,mast verticality,bearing layer current,single pile concrete pouring volume,filling coefficient,on-site wind speed and other main monitoring parameters,And carried out the construction site rig vehicle terminal hardware solution and pump truck vehicle terminal hardware solution and remote monitoring platform solution design.Secondly,in order to improve the measurement accuracy of single pile concrete pouring volume,analyzed the numerical model of the concrete pumping volume of the piston pump and the influencing factors of the pumping volume,proposed three concrete pumping volume measurement schemes based on the measurement of the displacement signal of the piston of the concrete cylinder,the measurement of the pressure signal of the oil inlet of the main oil cylinder,and the combination of the two signals,analyzed the measurement accuracy and deficiencies of each measurement scheme based on the field test results,Finally,it was determined that the system uses a combination scheme based on the pressure of the main oil cylinder and the displacement signal of the concrete cylinder to measure the concrete injection volume of a single pile.Then,design the selection and interface circuits of MCU selection and minimum system,data acquisition module,sensor,wireless communication module,alarm module,etc.of the on-board terminal hardware of drilling rig and pump truck.At the same time,completethe power module circuit and software and hardware anti-interference design.Thirdly,in order to verify the function of the system and the measurement accuracy of the monitoring parameters,Relying on the CFG pile construction work on site carry out the functional test and measurement accuracy analysis of the vehicle terminal.The test results show that the vehicle-mounted terminal can meet the site construction needs.This system realizes remote real-time monitoring of CFG pile construction process,Changing the “result control” of CFG pile into “process control”,which saves labor costs and improves the efficiency of construction management.It has certain economic and social significance.