| With underground project enlarged and the water conservancy project prospered at present, grouting technology has been widely used at home and abroad. However, Due to grouting engineering belonging to hidden project, the development of this technology is un-mature so far and the cases of theory falling behind practice and automation degree of grouting construction parameters monitoring and controlling technology being not high remains now in practice, such as that the study of crevasse rock grouting pressure affecting grouting effect is immature and feedback stability control of grouting pressure need to be studied. According to the methods of theory and practice grouting pressure affecting grouting effect and its ascertaining methods were analyzed in this paper, including design and making GYPC grouting pressure stabilization controlling system after mathematic model, and system analyses of basic theory, mechanism of action and open problem based on indoor experiments and field application. This paper gets the main research achievements as following:Mechanism of action and mathematic model of crevasse rock splitting effects and extending crevasse effects because of greater grouting pressure were analyzed and studied by the authors, and both of them impacting grouting effect was given, and grouting failure causes made by smaller pressure were analyzed in grouting pressure theory calculation. Grouting pressure determination methods were not sure as far, experience selecting methods, theory calculation methods, grouting experiment methods and comprehensive selecting methods were individually researched, in which main theory calculation methods included crevasse rock grouting pressure inversed calculation methods and hydraulic splitting theory calculation methods; main grouting experiment methods included normal grouting experiment, field grouting experiment, hydraulic splitting experiment and so on.Influence factors of grouting pressure stabilization were very complex, according to hydraulic characteristic of pipeline system, Influence factors of grouting pressure stabilization were specifically analyzed: damped characteristic of grouting hole strata, operating status of regulating valve and hydraulic characteristic of grouting pump and so on. Fluid body static balance equation and dynamic analysis calculation methods of grouting pipe system were studied in details. According to N-S equation of cement grout, mathematic model of grouting pressure stabilization was established by characteristic line methods, in which included dividing lattice, convergence condition of difference format, calculation of inertia factor, characteristic line difference methods of single pipe mixed cases and so on, the whole grouting pipes were simplified as a series of nonlinear algebra equations, these equations described pipes, equipment, grouting hole and regulating valves, and were solved by Newton iterative method. Established hydrodynamic model provided hydrodynamic theoretical basis and design thought for grouting pressure stabilization calculation software establishment.Calculation methods of grouting system pipe parts damp coefficients were analyzed and studied, those provided calculation control values for pressure stabilization calculation, including:â‘ cohesive grout calculation methods of friction resistance, part resistance and their damped coefficients in grouting pipe;â‘¡flow rules of grout in fracture were studied, cement grout were divided as pure Newton fluid, cohesive time varying Newton fluid, pure Bingham fluid, cohesive time varying Bingham fluid and so on;â‘¢instant flow pulse change rule and P-Q characteristic of three cylinder single-action reciprocating pump was studied;â‘£according to static and dynamic characteristic of regulating valve, linear characteristic flow, equal percent characteristic flow and parabola characteristic flow were studied, and provided relation between pressure and flow in every characteristic.Fuzzy control algorithm and normal PID control algorithm combined to form an entire intelligence algorithm by use of expert system design methods. GY grouting pressure stabilization control system was studied based on Fuzzy-PID compound control algorithm and hydrodynamic mathematic model, WINCC 6.0+STEP 7software was adopted to study superior system, SIEMENS S7-500 series PLC was adopted to study inferior system, superior system functions includes process flow, parameter installation, signal imitation, history trend curve and history data inquiry, data printing and so on.Innovation points of GYPC grouting pressure stabilization control system included: pressure stabilization control principle is based on pipe network hydrodynamic mathematic balance equation, its merits includes high accuracy and fine stability, pressure pulses were stabilized within installed pressure values 0.15MPa in 5-12 seconds by GYPC grouting pressure stabilization control system, the index is in the lead in the home, more superior than manual regulation and satisfied the needs of field application.Grouting pressure stabilization control imitation test stand of this subject initiated in the home, various tests of fluid flow characteristic in grouting pipe could be carried out. Flow characteristic tests of grouting pump and regulating valve were done, when pressure pulses were caused by unstable flow of grouting hole and other factors, they were stabilized within installed pressure values range by GYPC grouting pressure stabilization control system; based on system views firstly, relationship and influence within key composite parts of grouting pipes were looked as subject studied, simulation grouting construction was carried out and emulation of tests study was enhanced.Results of GYPC grouting pressure stabilization control system fracture rock curtain grouting engineering indicated, control principle of system is right, methods is feasible, effect is fine, filled up blank in the home, and applied into practice. At the same time large circulation grouting was adopted, grouting pressure should be controlled and adjusted in accordance with practical geological situation to obtain the optimal effect.
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