The deformation instability of surrounding rock and the collapse blocks are two common failure modes observed during construction underground caverns. Therefore, a comprehensive safety evaluation method (CSEM) for application cavern is presented in this paper. can be used to evaluate stability predict blocks, rapidly. First, prediction (DSPEM) mass established. It combines based on statistical analysis an inverse using measured data rock. This approach possesses unique characteristics...

A two-dimensional mesoscale modeling framework, which considers concrete as a four-phase material including voids, is developed for studying the effects of voids on tensile fracturing under plane stress condition. Aggregate assumed to behave elastically, while continuum damaged plasticity model employed describe mechanical behaviors mortar and ITZ. The fracture mechanism uniaxial tension are first detailed, followed by an extensive investigation void volume fraction fracturing. It found that...

The low efficiency of feedback analysis is one the main shortcomings in construction underground cavern engineering. With this mind, a method intelligent autofeedback and safety early-warning for proposed based on BP neural network FEM. training sample points are chosen by using uniform test design method, autogeneration FEM calculation file ABAQUS realized technique partition, information grouping, orderly numbering. Then, autoinversion mechanics parameters realized, automatic connection...

The widely used wet‐screening method in the experimental testing of hydraulic fully graded concrete inevitably results a gap between real mechanical parameters specimens and those corresponding wet‐screened therefore necessitates comparative study on their behaviors. To this end, two‐dimensional mesoscale modeling methodology is developed for simulating tensile fracturing behaviors concretes, extensive Monte Carlo simulations are performed. individual effects specimen size variation,...

Infilling rock joints widely exist in natural masses, and the shear failure of infilling plays an important role instability masses. In order to study mechanism joints, Particle Flow Code is used simulate direct test joints. The PFC models with different thickness are established firstly, then procedures simulation described. end, process simulated. Based on results, it can be concluded that mode changes increasing thickness, shearing joint rarely gives birth microcracks due existence material.

The cracking behavior and failure mode of a 78 m high concrete double‐curvature arch dam with weak upper abutment are investigated through performing analysis. mechanical is simulated using smeared crack model, in which combination the compression yield surface detection damaged elasticity concept employed to describe concrete. practical properties lower abutments firstly studied emphasis on its during overloading. Then, comprehensive sensitivity analysis carried out investigate influence...

Flocculation using modified clays is a technique widely applied in the management of harmful algal blooms (HABs). Polyaluminum chloride (PAC) clay an efficient flocculating agent HAB control; however its effectiveness black bloom still largely unknown. In present study, PAC-modified was used to flocculate under simulated flows. The deposition and resuspension matter/clay flocs impact spreading quartz sand were quantitatively studied. results showed that dosage 1.8 g/L (0.8 PAC 1 diatomite)...

The stability of rock masses is controlled by the shear behavior discontinuities, and it hard to investigate discontinuities at micro-scale using traditional physical test method. With this in mind, Particle Flow Code used simulate direct discontinuities. PFC model established firstly, its micro-properties are inversed proposed optimization inversion method based on asynchronous particle swarm algorithm. Then, simulation performed. results show that number microcracks gradually increases...

The calibration of micro-properties bonded particle model (BPM) is usually artificially accomplished by the means trial and error which has some intrinsic drawbacks such as high time consumption, arbitrariness, uncontrolled accuracy, etc. In order to overcome these shortcomings, optimization inversion method based on asynchronous swarm algorithm proposed estimate BPM in PFC. firstly established formulating objective function related constraint conditions, then procedure presented....

The optimization design method was rarely used to the gravity buttress of arch dam in past. With this mind, parametric description is given, and auto-calculation its exerting loads safety coefficient anti-slide stability are realized subsequently. Then, model procedures presented using asynchronous particle swarm method. Finally, ODGB software, which short for Optimization Design Gravity Buttress developed verified.

The network structure, initial weights and thresholds were optimized to solve some problems, such as over-fitting slow convergence rate in standard BP Neural Network. Combining the base seepage character of concrete dam, a uplift pressure monitoring model is established this paper with measured data actual dam . advantage presented tested validated by examples. It has positive significance application.

The mechanical property of rock discontinuities is one controlling factors deformation, strength and stability mass. Due to the limitation available constitutive models for within framework classical continuum mechanics, a new model presented by taking use direct methodology based on deformation behaviors discontinuities. In model, tangential stress curve dilation are divided into linear part before peak point, nonlinear softening after mathematical which can accurately characterize major...