The construction environment of tunnels is complex due to their unique spatial constraints, the diversity of rock properties, and the variability of construction machinery, which jointly lead to a substantial amount o...
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Particle crushing commonly occurs in granular materials and affects their structures and mechanical *** idealized particles in experimental single particle crushing tests with two loading points,natural particles are ...
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Particle crushing commonly occurs in granular materials and affects their structures and mechanical *** idealized particles in experimental single particle crushing tests with two loading points,natural particles are crushed under multicontact *** date,the criteria and patterns of par-ticle crushing under multicontact conditions are not fully *** using the three-dimensional discrete element method,this report explores the effect of multicontact loading on the crushing criterion of a single particle,the crushing pattern,and the relationship between the particle crushing strength and loading *** particles are modelled as aggregates of glued Voronoi *** numer-ical results indicate that the logarithm of the mean principal stress has a good linear correlation with the coordination *** a specific coordination number,the number of child particles presents a significant normal *** a specific number of child particles,the volumes of child particles can be statistically described as normal or gamma *** typical models are proposed to qual-itatively analyse the relationship between the loading distribution and crushing *** relevant conclusions can be helpful in engineering practice and in further studies on crushable granular materials via the discrete element method.
In discrete element method(DEM)simulations,multi-sphere(MS)clumped and convex particles are two main particle models that are used to study the mechanical behaviours of granular *** interest is the evaluation of the e...
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In discrete element method(DEM)simulations,multi-sphere(MS)clumped and convex particles are two main particle models that are used to study the mechanical behaviours of granular *** interest is the evaluation of the effect of multiple contacts between clumped particles or single contacts between convex particles on the mechanical behaviours of granular *** this context,a series of drained triaxial compression tests were conducted on convex true(CT)ellipsoids and MS ellipsoids with aspect ratios(ARs)ranging from *** microscale results indicate that at a given AR,the critical friction angleφ_(c)changes with the particle type,whereas the peak friction angleφ_(p)is nearly independent of the particle *** anisotropic analysis provides underlying mechanisms of the shear strength evolution from two ***,the anisotropies of granular materials are essential to shear strength as the deviatoric(q)-to-effective mean(p′)stress ratio can be expressed as the sum of the anisotropies,i.e.,q/p'≈0.4a_(c)+0.4a_(n)+0.6a_(t),where ac,an and at are the normal contact anisotropy,normal contact force anisotropy and tangential contact force anisotropy,*** all samples,a_(c)and a_(n)underpin the shear strength and are influenced by the particle *** similarφ_(p)displayed by the CT and MS ellipsoids does not translate to similar a_(n)and a_(c)but similar a_(c)+a_(n)for the two particle *** addition,owing to their larger a_(c)+a_(n),the CT ellipsoids have a higherφ_(c)than the MS ***,there is a satisfactory linear relationship between q/p'and ac within strong and non-sliding(sn)contacts a_(c)^(sn)(i.e.,q/p′=ka_(c)^(sn)),where k is the fitting ***,in the peak state,the subtle difference in shear strength is attributed to the greater acsn in the CT ellipsoids than in the MS ellipsoids that is counteracted by the smaller ***,in the critical state,the greater difference in a_(c)^(sn)between the CT
According to the drawing load characteristics of horizontal rectangular anchor plate in red clay foundation, the vertical drawing model test of horizontal rectangular anchor plate in saturated red clay foundation is c...
Multi-sphere clumps are commonly used to simulate non-spherical particles in discrete element method *** is of interest whether the degree of local non-convexity λ affects the mechanical behaviour of granular materia...
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Multi-sphere clumps are commonly used to simulate non-spherical particles in discrete element method *** is of interest whether the degree of local non-convexity λ affects the mechanical behaviour of granular materials with the same non-convexity η.A series of discrete-element-method biaxial shear tests are conducted on rough particle packings with rη=0.075 and different λ values(ranging from 0.134 to 0.770).The microscale results show that the contact type changes with an increase in λ.However,the critical strength is independent of λ.The evaluation of the contributions of different contact types to the critical shear strength and a detailed analysis of the anisotropies help clarify the microscopic mechanisms that result in the independence of the critical shear strength from λ.
The physical and mechanical properties of soils change when soils are contaminated by oil products. This study investigates the effect of diesel oil contamination on the geotechnical properties of granitic residual so...
The physical and mechanical properties of soils change when soils are contaminated by oil products. This study investigates the effect of diesel oil contamination on the geotechnical properties of granitic residual soil. To better understand the behavior of oil-contaminated granitic residual soils, an experimental laboratory investigation was performed on granitic residual soil that was polluted by different amounts of diesel (0 to 15% by soil dry weight). In this paper, the geotechnical properties of clean and contaminated samples, including compaction characteristics, Atterberg limits, shear strength parameters, disintegration rate, and permeability coefficient, were evaluated through tests. The test results indicate that diesel oil has adverse effects on all aspects of the geotechnical properties of granitic residual soil. With the increase in oil content, shear strength parameters, compaction characteristics, and Atterberg limits appear to have different degrees of decline, and granitic residual soil is more likely to disintegrate.
Using coal gangue as subgrade filler can not only solve the environmental problems of coal mine waste accumulation, but also save the subgrade cost, which has the important theoretical and practical significance. A se...
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Using coal gangue as subgrade filler can not only solve the environmental problems of coal mine waste accumulation, but also save the subgrade cost, which has the important theoretical and practical significance. A se...
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Methods for calculating the uplift capacity of horizontal anchor plates have the problem of artificially distinguishing shallow and deep buried types in advance, but the classification standards differ greatly. Based ...
Horizontal pullout mechanism and bearing capacity research of vertical square anchor plate has the problem of artificial distinguishing shallow and deep buried types, but non-uniform definition standard. The presented...
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