Research On TBM Construction Schedule Simulation Of Diversion Tunnel Based On Sensitivity Analysis

Diversion tunnel is an important and indispensable part in hydraulic engineering and faces with a lot of challenges such as complex construction condition,uncertain construction environment,tight construction schedule,etc.,which leads to a great difficulty in the construction process.Tunnel Boring Machine(TBM)method has been a prevailing tunneling method for tunnel excavation,which not only can achieve rapid excavation technically,but also has high comprehensive benefits.However,as TBM excavates tunnels by tunnelling and restoration,the construction of diversion tunnel has become a complex system involving numerous construction parameters such as advance rate,tool changing,vehicle amount,etc.These parameters has the characteristics of large quantity and wide data range,each tiny changes can lead to the possibility of duration changes.The difference between actual duration and planned duration will cause the difficulty in schedule management.This paper makes an in-depth study on the problems mentioned above and obtains the following results:1.Considering the impact of simulation construction parameters in the simulation model on construction duration,TBM construction schedule simulation model of diversion tunnel has been established based on duration sensitivity analysis.According to the construction conditions of diversion tunnel,TBM construction schedule simulation model of diversion tunnel has been established considering the sensitivity analysis,which was built based on traditional construction schedule simulation theory couples Critical Path Method(CPM)and Cycle Operation Network(CYCLONE).The influence of all the simulation parameters to the schedule was analyzed,which could overcome some limitations of parameter identification in sensitivity analysis.According to the characteristics of hierarchically modeling of simulation model,the sensitivity analysis of control hierarchy,implement hierarchy and entire duration was studied.Combining the idea of multi-factor test,the main effect of parameter on duration sensitivity was determined,and the interaction effect of parameter combination on schedule sensitivity was analyzed.The general law of parameter influence on duration was revealed and the key construction parameters were identified,which provided an important theoretical basis for the decision of construction organization design and operations management in construction site.simulation model on construction duration,multi-factor sensitivity analysis of diversion tunnel TBM construction duration has been conducted using uniform test design method.2.Considering the impact of all simulation construction parameters in theCurrent researches only analyzed the effect of some main factors on duration and the results cannot guide the construction effectively.The multi-factor sensitivity analysis method of diversion tunnel TBM construction duration was proposed.The testing program of sensitivity analysis based on portion factor test was built by the uniform test,and the effect of all the simulation parameters on entire duration was analyzed.This can reduce the test amounts effectively with reasonable reliability and overcome the limitations of test conduction caused by numerous parameters.The test data were analyzed by the regression analysis method and the key construction parameters that affected the duration were output,which provided an important theoretical basis for the reasonable parameter selection and effective control.3.Considering the combined impact of process duration and simulation construction parameters in the simulation model on construction duration,comprehensive sensitivity analysis of diversion tunnel TBM construction duration has been conducted using orthogonal test design method.All construction simulation parameters in the simulation model were selected as the input parameters and then the factors and factor levels for the orthogonal test were defined.A set of test program for sensitivity analysis of diversion tunnel TBM construction duration was established according to the orthogonal design principles of ‘uniformly dispersed,tidy comparable'.Integrity and level of simulation model was taken into account,therefore sensitivity analysis of process duration on total duration,sensitivity analysis of construction parameters on process duration,and sensitivity analysis of construction parameters on total duration have been conducted.Sensitivity effects of process duration,construction parameters and parameter combinations on the total duration have been analyzed comprehensively.Analysis of variance was used to analyze the results of the test data.Main effects and interaction effects of construction parameters on construction duration have been outputted,which made the key management of construction parameters and machinery possible.4.Considering the global impact of simulation construction parameters on construction duration,global sensitivity analysis of diversion tunnel TBM construction duration has been conducted using Extended Fourier Amplitude Sensitivity Test(EFAST).A conversion function with common independent parameters was introduced into the simulation model of all construction simulation parameters.An integer frequency was defined for each construction and independent-parameters periodic function was form.Fourier Series Spectrum was calculated using flourier transform and the total variance was obtained.Relying on Sobol variance decomposition thought,parameter's main effects of processes duration and construction parameters were outputted,by which the key process parameters and processes could been recognized.The each proportion of processes duration and construction parameter's interaction summation on total duration has been outputted.This output assisted the recognition of key process and construction parameters,and verified recognition results,which provided a reference for on-site construction management and schedule control.5.The three methods used for the sensitivity analysis of diversion tunnel TBM construction duration have been compared.The features and benefits of each method were determined,which provided a reasonable basis for the method selected for different target of construction duration sensitivity analysis.The sensitivity analysis of diversion tunnel TBM construction duration has been conducted using orthogonal design method,uniform design method and EFAST method.The analysis was on the basis of the duration simulation results and was relied on practical engineering.These three methods' convince of experimental design has been compared in accordance with the testing program principles of the three methods.The deviation of each method's result has been calculated while maintaining the same amount of tests and the same factor level.Then the accuratenesses of the calculation results of the three methods have been compared.The output conclusions of sensitivity analysis using the three methods have been compared.Features and advantages of each method have been cleared,offering reasonable basis for selection of sensitivity analysis methods while targeting different goals.