The Study And Development Of The Expert System Of Underground Cavern Group Construction Based On The Internet Of Things

Underground cavern group construction is a complex system engineering,which is affected by a variety of complex natural geological conditions and manyother unknown factors. In view of the randomness, sudden, uncertainty and highlyempirical as well as other characteristics of the construction process of undergroundcavern group, the Internet of Things Technology (ITT) and other advancedtechnologies and methods are introduced in this paper. In addition, a systematicanalysis and research on the four main aspects (information collection, projectschedule, engineering safety, engineering warning) of the construction process ofunderground cavern group is carried out. Then an expert information system basedon ITT for the construction of underground cavern group is developed. The mainresearch contents and results of this paper are as follows:(1) Based on ITT, a real-time acquisition scheme for all kinds ofconstruction information of the underground cavern group is proposed and areal-time data acquisition platform for construction information of theunderground cavern group is built.ITT is first applied to the construction information collection of undergroundcavern group, with respect to the characteristics of various types of informationproduced in the construction process of underground cavern group; three differenttypes of information acquisition methods are proposed. Then information in theconstruction process can be collected timely and wirelessly. The problems of poortimeliness and highly complexity as well as other shortcomings of currentinformation gathering process in the construction of underground cavern group aremade up, and thus can provide real-time data for the scientific management andscientific decision in the course of construction of underground cavern group.(2)A time-varying construction schedule risk prediction method based onBayesian theory for construction of underground cavern group is put forwardin this paper; meanwhile, combined with the risk control concept ofconstruction schedule, a real-time risk control expert system for constructionschedule based on Bayesian theory is set up. Bayesian theory and real-time simulation technology are introduced into theprediction of underground cavern group construction schedule in this paper, atime-varying construction schedule risk prediction method based on Bayesiantheory for construction of underground cavern group is put forward. In the method,mean value and variance of unit workload construction time are chosen as randomvariables, and the probability distribution forecast of remaining work time of underconstruction process and work time of new construction procedure can be revisedand improved constantly according to the actual record information of theconstruction field. At the same time, combined with flexible network planningsimulation method, completion risk of the overall construction schedule of the lateproject can be predicted. With the method of this paper, construction scheduleprediction results are highly consistent with actual engineering practice, and thusthe method can play a practical role in promoting the development of probabilityprediction methods for the construction schedule of underground cavern group.(3)In this paper, a suitable method to establish numerical models forreal-time simulation is given and the real-time mapping relationship betweenactual construction state and numerical models is set up. Besides, a real-timenumerical simulation method based on numerical simulation technology forconstruction structural safety of underground cavern group is proposed.Through in-depth analysis of actual construction state and constructionnumerical simulation state, main factors of the two are given. Then by bringing inthe concepts of collection in mathematics, the real-time dynamic mapping relationsbetween the two states are established. The simulation of actual constructionprogress, unexpected adverse geological conditions and support measures oflarge-scale refinement numerical models can be completed timely andautomatically, and the aim of real-time numerical simulation for constructionstructural safety of underground cavern group is realized. Thus it can provideimportant reference for field engineers to make decisions and commands.(4)Integrated innovation point (2) and (3), the coupled real-time simulationmethod of structural safety for construction period of underground caverngroup is proposed. And based on structure safety and schedule coupledsimulation method, a treatment expert system for unexpected adversegeological conditions during construction is put forward. Construction safety and progress of large underground cavern group are greatlyinfluenced by sudden adverse geological conditions, thus real-time determination ofthe combined affects which sudden adverse geological conditions have onconstruction structure safety and schedule has important engineering significance.In this paper, sudden adverse geological conditions are mapped to numericalmodels. And based on the real-time numerical simulation results, structural safetyof the adverse geological areas is assessed. Then appropriate measures forconstruction states that don‘t meet the security requirements can be put forward.Through the real-time simulation of treatment effects, decided treatments in formsof construction parameters are sent back to the construction schedule control system,in this way, the system can assess the effects of treatments on overall constructionschedule. The system implements the on-site office integration of undergroundengineering construction safety and progress control and can provide technicalsupport for the security and progress control of the on-site construction ofunderground works.(5) Based on the idea of strength reduction and combine with the real-timenumerical simulation method mentioned in (3), a calculation method based onreal-time numerical simulation of the construction period of the undergroundcavern group surrounding rock deterioration damage reduction is proposed.Surrounding rock deformation dynamic early warning indicators andstandards of surrounding rock under certain construction status during theconstruction phase can be calculated through that method, and thus it canrealize the aim of dynamic security warning during the construction phase.In consideration of the fact that excavation disturbance can cause thepropagation of deterioration and damage zones in inner of surrounding rock, thispaper introduces the idea of strength reduction which is commonly used in theexcavation of slopes and proposes a calculation method based on real-timenumerical simulation of the construction period of the underground cavern groupsurrounding rock deterioration damage reduction. In this method, the range ofdeterioration damage zones of surrounding rock is divided by the yield proximityindicators. In each calculation only the strength parameters of deterioration damagezones are reduced, the strength of parameters should be reduced until the numericalcalculation does not converge, then a curve of surrounding rock deformation andthe reduction factor can be got; the curve can be divided into three deformation parts, namely the uniform part, the acceleration part and the destruction part.Boundary values of the three parts can be used to establish the dynamic earlywarning standards of that excavation status, and then the aim of dynamic securitywarning during the construction phase is realized.(6) Based on multi-level fuzzy comprehensive evaluation method, acomprehensive safety evaluation method according to observed behavior ofunderground cavern group is proposed.Based on in-depth analysis and extensive research on the security andmonitoring design of underground cavern group, a structure safety evaluationsystem of underground cavern group based on measured information is establishedin this article. Index weights in the system are determined through analytichierarchy process and expert scoring method. Then by comprehensive applicationof two kinds of operators,―the multiplication and max operator M(,∨)‖and―themultiplication and addition operator M(,+)‖, the weight vector of fuzzycomprehensive evaluation method and the composition of fuzzy relationship matrixcan be improved. With fully consideration of the influence of most dangeroussectional area on overall safety evaluation results, unstable risk factors can be betterdelivered to upper layer, thus the final evaluation result of structure stability is moreauthentic and believable. Furthermore, this method also provides a new way ofthinking for overall safety evaluation of underground cavern group.(7) In conclusion, based on ITT, a construction expert information systemof underground cavern group is developed and other auxiliary functions of thesystem are briefly introduced in the paper as well.