Research On Back Analysis Of Wet Deformation Parameters Of Earth-Rock Dam Considering Uncertainty

With the orderly progress of the Fourteenth Five-Year Plan,the total amount of dam construction in my country has always maintained a relatively large base.According to statistics,earth-rock dams account for 95% of the total number of reservoirs built in the country.It can be seen that earth-rock dams play an extremely important role in water conservancy projects.The advantages of earth-rock dam are clear is convenient and quick to construct,and it has a wide range of adaptability.In comparison with other kinds of dam construction,it consumes less manpower and material resources.However,there are also factors such as seepage stability in earth-rock dams that seriously affect engineering safety.Therefore,it is very important to pay attention to the deformation and settlement of earth-rock dams.With the gradual development of modern methods for the construction of earth-rock dams,many factors affecting the safe operation of earth-rock dams have been discovered one by one.With the changes of reservoir water level,groundwater level,and rainfall infiltration,the state of coarse-grained materials in the dam body changes from dry to wet,which softens the particles and produces wetting deformation,which in turn leads to subsidence of the dam.It will have a serious impact on the safe operation of the project.Therefore,it is very important to carry out reasonable analysis and prediction inversion of wetting deformation.This paper selects earth-rock dam materials for triaxial humidification test,selects a suitable constitutive model,performs parameter calculations,and then develops back analysis of earth-rock dam wetting deformation parameters.However,due to the inherent uncertainty in the deformation of the earth-rock dam and the uncertain factors generated in the test process,the constitutive model parameters obtained by calculation will have a certain deviation from the parameters in the actual project.In order to fully consider these uncertainties and obtain the parameters that reflect the wet deformation of the earth-rock dam as true as possible,the cloud theory is introduced into this paper,and the relationship between the constitutive model and the actual deformation is considered,and the inversion research is carried out.The principal research contents of this paper are as follows: 1.Calculate the constitutive model parameters derived from the experimental results.Through the indoor triaxial humidification test on the sample,the Duncan-Chang E-v model is chosen as the constitutive model.Then the constitutive model parameters are calculated.By referring to practical engineering problems,the parameters to be retrieved are determined.2.Perform finite element positive analysis on the parameters.Assuming that the selected inversion parameters of the constitutive model all conform to the pan-normal cloud distribution,the calculated Duncan-Chang parameter is divided into 5 parameter intervals according to the value range,and the cloud digital characteristic value of the interval is calculated.The cloud model builds training samples.The parameter training samples are substituted into the calculation in the ANSYS software that has been re-developed,and the corresponding lateral and axial deformations are obtained.3.Construct a cloud reasoning inversion model considering uncertainty.The parameter training samples and their corresponding deformation values are used to construct the cloud inference model before and after,and the nonlinear mapping relation is constructed through "SOFT AND",and the uncertain cloud reasoning model is established.4.Verify the feasibility of the cloud reasoning inversion model.The actual triaxial test calculation results are directly substituted into the uncertainty cloud reasoning,Activate the inversion model of wetting parameters,then the parameter substitution to the analysis of finite element are calculated lateral deformation and axial deformation values..To analyzing the deformation and inverse finite element analysis is obtained after calculating the deformation value is compared,the conclusion shows that this uncertainty cloud inference algorithm can better invert the wetting deformation parameters,and the result has higher accuracy.