Abstract Tunnel excavation in Boom Clay formation, Belgium, highlighted an anisotropic behaviour related to its bedding planes. Hollow cylinder tests mimicking tunnel excavation under laboratory conditions confirmed the isotropic convergence of samples cored perpendicular to the bedding and the anisotropic behaviour of samples cored parallel to the bedding. This article investigates the possibility

Abstract While the application of nanoindentation technology has made great progress in cemented materials, the nanoindentation data show great discreteness. This study proposes an efficient procedure for concrete with coarse aggregate grinding and polishing to provide low surface roughness through a lot of polishing experiments. An integrated investigation, using SEM-EDS and nanoindentation, is performed

Abstract The reliability analysis is one of the main methods for the quantitative analysis of the safety in the geotechnical engineering. This method can provide the failure probability with a clear physical meaning. Due to the complex structure of high earth-rock dams and the non-linear characteristics of the material properties, it is very difficult to perform the reliability analysis on such large

Abstract Studying the characteristics of tensile and shear cracks in a rockburst event is crucial for understanding the rockburst mechanism. In this study, several specimens were tested under biaxial compression, and the released acoustic emissions (AEs) of the resulting tunnel rockburst event were recorded. Based on the AE energy and dominant frequency parameters, the different AE characteristics

Abstract Many construction projects such as bridges, barriers, road construction, etc. use rigid or flexible retaining walls. Seismic behaviour analysis of such structures is difficult and complex due to the complexity of the relationships governing wall behaviour. Three methods of field observation, laboratory simulation and numerical modelling can be used for this purpose. In this study, dynamic

Abstract Due to the negative environmental impact of cement production, partial replacement of cement with by-products and wastes has been drawn much attention. However, the reduction in binder fraction can affect the fresh and mechanical properties of cement-based materials. In this study, the effects of nano and micro Fe3O4 on the fresh and mechanical properties of plain mortar as well as mortar

Abstract Poor adhesion of synthetic macro fibers to a cementitious matrix limits their reinforcing capacity when used in fiber-reinforced cementitious composites (FRCCs). As a remedy to this problem, high concentrations of fibers must be incorporated into such mixtures, which makes their dispersion in fresh mixtures difficult to achieve. Several strategies have been adopted to improve bonding between

Abstract An overview of the effect of mineral additives on hydration reactions in ternary cement systems is of high importance for concrete design and durability. In this paper, the combination effect of limestone filler and slag on hydration reactions in ternary cements was investigated. Tests were carried out on cement pastes with various replacement levels of cement by limestone filler and slag

Abstract In the Eurocodes, the notion of reliability is presented and expressed in terms of the target failure probability. The three reliability classes (RC1, RC2 and RC3) are based on assumed consequences of failure and exposure of construction works to potential hazards, their levels of safety and probability of failure are represented by the reliability index β. The normal (most current) situation

Abstract Recycled construction and demolition (C&D) materials are widely used in engineering fills to reduce the pressure on the environment. This study intended to investigate the effect of particle sizes and sand contents on mechanical behavior of recycled C&D materials using triaxial tests. The results demonstrated that the water absorption rate of crushed bricks (CB) was much higher than that of

This paper investigates the seismic capacity and collapse mechanism of dry-joint masonry towers built with different ancient construction techniques at the Caria and Pamphylia regions in Turkey. A discontinuum type of analysis is performed, where masonry towers are represented as a system of individual rigid blocks based on the discrete element method (DEM). The dimensions and the morphology of the

Following the assumptions proposed by Davis and Raymond, an analytical solution for one-dimensional nonlinear consolidation of double-layered soil under constant loading is derived by introducing an improved continuous drainage boundary condition. The effectiveness of the present solution is assessed by comparing against other existing analytical solutions and laboratory consolidation test results

This study had a triple environmental objective. First, to reuse various industrial wastes (i.e., bottom ash, slag, and construction and demolition waste) as coarse aggregates in porous concretes. Second, to develop a material capable of eliminating noise, another environmental pollutant, in acoustic barriers. The third objective was to produce construction materials composed primarily of wastes with

The elasto-plastic behavior of the Fontainebleau sandstone is studied from experimental and numerical points of view on the basis of a series of conventional triaxial compression tests. Five distinct stages of the axial strain curve are quantified in terms of four stress thresholds (crack closure stress σcc , crack initiation stress σci , crack damage stress σcd and short-term peak strength σp ). The

In deep buried rock engineering, in situ stress is a significant factor affecting the mechanical response of rocks to dynamic loads. This work focuses on the effect of confining pressure on dynamic deformation of rocks. Considering the limitation of observation in laboratory experiments, numerical simulation method is adopted. The numerical model of split Hopkinson pressure bar test system with confining

This study provides experimental evidence of the correlation between different fabric tensors in 2D granular assemblies subjected to shearing. Two testing assemblies with different elliptical rods were used and the shearing tests were conducted in a tailor-made biaxial cell. Both the rods and cell were produced using the 3D printing technique. Throughout the shearing, three fabric tensors, i.e., the

Erosion, both surficial and internal, presents risks to performance and stability of earth dams, dikes, and water barriers. The consequences and severity of erosion incidents are amenable to soil erodibility. This study investigates the efficiency of additives/stabilizers in modifying soil erosion characteristics. Erosion parameters, namely coefficient of soil erosion, critical shear stress, and erosion

Rock masses are highly characterized by size effect due to the existence of complex discontinuities, which could be reflected by representative volume element (RVE). This study exemplified calculation of RVE in Datengxia sluice rock mass analysis with consideration of anisotropy, which extends the application of traditional RVE featured by three-dimensional (3-D) equal sizes. Specifically, fracture

Clay and silt have complicated effects on the undrained behaviour of sands. To study the influences of low clay and silt contents on the undrained behaviour of sands in the clay–silt–sand mixtures, sands with three different fine contents (0%, 5% and 10%) and three different fines mixing ratios were investigated based on the consolidated-undrained test by a strain-controlled triaxial testing system

We investigate the mechanical characterisation of mortars incorporating ferronickel slags (FNS) as partial substitution for cement. The studied slags come from the ferronickel production in New Caledonia. The microstructural characterisation shows that these slags are polycrystalline heterogeneous material mainly composed of forsterite, quartz and enstatite in addition to silica glass. Cement is replaced

For the sake of economic design and safety requirement, the prediction of active earth pressure on laggings between stabilising piles is of great significance. However, the nonlinear distribution of active earth pressure on laggings between piles cannot be accurately predicted by using the classical theory. In this study, a novel method of calculating active earth pressure on laggings between piles

Several studies have examined the geotechnical behaviour of energy piles; however, the behaviour of piled-raft foundations containing thermal piles is not fully understood. Because piled-raft foundations are optimally designed to bear mechanical loading from the top structure, the energy piles induce extra stress and bending moments on the raft foundation (slab) from the thermal loads, which may cause

The methods available to predict the strain and tension of geogrid are regularly based on two-dimensional condition, however, the three-dimensional deformed shape of geogrid is seldom considered in the literature. This paper proposed an analytical method to calculate the settlement of reinforced piled embankment considering three-dimensional deformed geogrid, in which the arching effect, the bearing

Processed spent bleaching earth (PSBE) is the end product derived from the processing of de-oiled spent bleaching earth (SBE) after the oil is recovered. Bleaching earth is very fine powder clay, and its main component is silicon dioxide used for refining process of palm oil and its by product is known as SBE is commonly disposed to landfill. The bleaching earth that is used for decolouring during

One of the major problems caused by the construction and demolition of buildings is the environmental pollution due to the disposal of the large volume of generated waste materials. In addition to the protection of environment, the recycling and reusing of the waste materials are an economical measure. In this research, the viability of using the recycled brick powder as a partial or full replacement

The influence of a trench in the behaviour of a rigid, strip foundation is numerically investigated under the prism of impedance functions. Both the soil and the foundation are simulated by 2-D plane strain elements. The soil half-space finite element model is truncated using absorbing boundaries. The foundation has three degrees of freedom: vertical and horizontal translation and rotation. Therefore

Considering the changes of permeability and Biot’s coefficients, the closed-form elastic-brittle-plastic solution of lined circular tunnels was proposed employing a Mohr-Coulomb non-associated flow rule. The influence of the reserved deformation of lining structure, permeability and Biot’s coefficients on the plastic radius, displacement and water inflow was studied. With an increase in permeability

The ultimate bearing capacity of a ring footing on loose sand deposit, with an inclusion of a dense sand layer on its top, has been determined numerically in a bound form by following the finite element limit analysis (FELA). The friction angles ϕ1 and ϕ2 were varied from 40° to 46° and 30° to 36° for the top dense sand and the bottom loose sand respectively. The Mohr-Coulomb’s yield criterion has

This paper presents an experimental investigation on lightweight aggregate mortars containing high volume cement replacement materials. For this purpose, expanded perlite (EP) and expanded vermiculite (EV) are used as the lightweight aggregate (at sand replacements of 50% and 100%), while ground granulated blast furnace slag (GGBS) (35% and 70% replacement level) and fly ash (25% and 50% replacement

Owing to their specific sedimentary or weathering formation history, most soils confronted in civil engineering can be categorised into clayey and sandy soils. In view of the great mechanical difference, particularly the distinct liquefaction resistance, then precisely simulate the mechanical and liquefaction characteristics of different type soils become an important research issue in seismic design

In this study, under the skimming flow regime, energy dissipation was investigated with data-driven methods. The data set obtained from the laboratory experiments were modelled by different machine learning (ML) methods, including support vector machine (SVM), K-star (K*) algorithm and artificial neural networks (ANN). Afterwards, for the first time in the literature, linear and nonlinear ensemble

The use of clays, especially bentonite clays in composites, is one of the practical and cost-effective ways for engineers to absorb heavy metals. On the other hand, automatically obtained mechanical properties of these composites, especially plastic concrete (PC) made by adding bentonite clay to the ordinary concrete mixture, can be useful in reducing the cost and optimising the time of the cutoff

Only a seismic analysis of tunnels at a single-phase site can be performed using the commonly used finite element software owing to the lack of a dynamic two-phase element. The seismic analysis of tunnels at a saturated site is primarily based on OpenSees or self-compiled programmes, the majority of which are limited to uniform or horizontal-layered sites owing to the related issues of the inconvenience

Buildings in towns and villages suffer heavy damages and losses during earthquakes. In this study, six types tire–granular material composite foundations were fabricated and tested under cyclic reversed loading to investigate the energy absorption and dissipation effects of such composite foundations applied to village buildings. The effects of different axial loads (100, 200 and 300 kPa), tire arrangement

In order to study the relationship between multifractal characteristics of particle-size distribution (PSD) and unsaturated hydraulic conductivity, taking the Hunan clay as the research object, we analysed the particle composition of the whole particle size range by a laser particle size analyser, and discussed the multifractal characteristics of PSD by using the fractal theory. The soil–water characteristic

Republic of North Macedonia is a seismic prone country with a long tradition and positive experience in the field of seismic design of new and strengthening of the existing buildings up to pre-defined levels of seismic protection. The principal seismic design philosophy which is stipulated in the regulations is based on protection of human lives against strong earthquakes and partially on controlled

This experimental investigates presents the use of three types of plastic wastes as fine aggregates in concrete as an effective way to deal with the scarcity of natural aggregate and problems related to disposal of plastic. This work emphasises on using plastic waste from different source such as water drink bottle, compact disk, and plastic cover of water drink bottle to substitute fine aggregate

Different treatment strategies have been explored in a quest to improve the properties of recycled aggregate concrete (RAC). The improvement strategies are directed towards the removal of residual layers of old mortar on the recycled coarse aggregate (RA). The removal of old mortar layer improves the bond between the new mortar and the RA that makes the quality of RAC better. Efforts have been made

Lining is gaining acceptance in underground excavations because of its reinforcing and protecting capacities. The purpose of this paper was to derive an analytic expression based on the complex variable method to describe the behaviour of a tunnel with a liner of finite thickness. The stress functions have been expressed as Laurent series where the infinite undetermined coefficients are obtained using

Permeability is the key factor to control long-term stability of surrounding rock of high level radioactive waste (HLW) geological repository. In view of the low permeability of the intact granite in Beishan area, the preferred site for HLW repository in Northwest China, argon was used as the fluid medium to measure the gas permeability of Beishan granite under hydrostatic pressures and cyclic loading-unloading

The field bearing plate method test is the most commonly used method to determine rock mass deformation parameters. Currently, due to the effect of the applied test stress, the difference between the rheological model curve and test curve can be significant, namely the model cannot reflect the effect of the applied stress. In this study, a seven-component viscoelastic combination model that considers

Due to long-term coupling of ground stress and water pressure during operation processes, lining concrete will experience different degrees of cracking and spalling, which seriously affect the safety of tunnels during service. In this paper, lining concrete seepage tests under different confining pressures are performed; the mechanical properties and acoustic emission (AE) responses during the loading

We present a strong nonlocal hydromechanical model formulated based on state-based peridynamics for simulating strain localisation in unsaturated geomaterials. The governing equations are integro-differential equations in which length scales are assumed for both the skeleton deformation and pore fluid flow. Recently proposed hydromechanical correspondence principle is adopted to implement the classical

The Meuse/Haute-Marne underground research laboratory was built in the Callovo–Oxfordian (COx) clay formation for the purpose of assessing the feasibility and safety of a deep geological formation to host an industrial radioactive waste repository (Cigéo project) in France. Some observations related to the drifts oriented in the direction of the major horizontal stress remain to be theoretically and

In order to study the impact of internal erosion at the scale of an engineering structure, a hydro-mechanical continuous modelling approach considering suffusion is needed. It requires a relevant mechanical model for granular soils considering the f c -dependency ( f c : fines content) and a hydraulic model for suffusion to control the changes in the fines content. To this purpose, the mechanical models

Due to the rugged topology, bridges in Western China often contain piers over 40-m height. The seismic responses of these tall pier bridges are usually estimated using nonlinear time history analysis (NTHA) procedure, which is rigorous but time consuming and computational demanding when plastic performance is involved. This paper modified a procedure previously proposed estimating nonlinear seismic

The geotechnical properties, chemical reaction mechanisms, and microstructure evolution of alkali-activated fly-ash-stabilised construction and demolition waste (C&D) and the main components recycled concrete aggregate (RCA) and clay brick (CB) were investigated in this study. The alkali activator was a composite solution of sodium hydroxide and water glass. XRD, FTIR, SEM, and UCS testing methods

To explore the microscopic mechanism underpinning the dynamic characteristics of saturated loess, dynamic triaxial tests were conducted on saturated loess in Xianyang City, China. The tests were performed under dynamic loads of different waveforms, confining pressures, frequencies and amplitudes. Under each dynamic load, the test included two states: one stopped after 12 loading cycles, and the other

In this research, three- dimension finite difference method was applied to simulate the tunnel excavation by earth pressure balance (EPB) boring machine of Tehran Metro Line 7 tunnel in Iran. Sensitivity analysis and parameter identification was carried out by Morris Elementary Effect method to evaluate the relative sensitivity of model for each input parameter. Then, artificial neural network (ANN)

In this study, the effects of polypropylene fibre content and length on the mechanical properties of municipal solid waste incineration (MSWI) bottom-ash-mixed (BA-mixed) clay soil were investigated through triaxial tests. By varying the fibre length and content, the stress-strain relationship and strength characteristics of polypropylene fibre-reinforced soil were analysed under different confining

The effects of elevated temperatures on concrete containing glass waste are investigated. Addition of 15% waste glass powder by weight of cement is performed to obtain glassy concrete (GC). This study provides several recommendations to enhance construction work and services by using glass waste and explores ways to increase durability for improved construction performance and to meet recycling goals

The mechanical properties of interactive marine-terrestrial (IMT) deposit soils differ from those of other deposits as a result of the complex sedimentary environments in which they are found. The creep behaviors of IMT deposits in Ningbo, China were studied via triaxial drained creep testing. The theory of fractal derivatives was then applied to develop a fractal merchant model, in which a fractal

This article presents the results of a set of 28 large-scale triaxial tests, including 12 consolidated-drained (CD) static tests and 16 consolidated-undrained (CU) dynamic tests, on an artificially cemented gravel. The strength, dilatancy, stiffness and damping behaviour of both the cemented and the uncemented specimens are compared. Cementation is found to have interrelated effects on increasing the

Many foundations, such as those of industrial equipment, offshore structures and wind turbines, have to operate under repeated loads. Shakedown analysis is a powerful method that yields a straightforward calculation of a load limit below which the foundation will be stable under repeated loading. In this article, using the upper bound shakedown theorem by means of displacement finite element method

Junked tires encased slags pile composite foundation (JTES pile composite foundation for short) is a new method for treating soft soil ground. To study the vertical load-settlement characteristics and load-transfer mechanism of JTES pile composite foundation, vertical static load comparison tests in different loading conditions were investigated herein. The test results show that, the load-settlement

One of the most important material used in the construction industry is concrete. Adaptability with steel also provides the necessary tensile strength for constructing towering structures. However, concrete is susceptible to shrinkage during the curing process which produces micro cracks. These tiny fissures provide gateways to fluids for entering into concrete. The fluids undergo various reactions

This study investigates the carbonation behaviour of alkali-activated fly ash-based (AFA) concretes. AFA contains 20.67% of unburned carbon. GBFS and OPC were used as sources of calcium (20%). A mixture of NaOH and Na2SiO3 was used as activator. OPC concrete was used as reference material. AFA/GBFS, AFA/OPC and OPC concretes, with and without reinforcing steel, were exposed to accelerated carbonation

Ancient Chinese heritage buildings have high historical and artistic value. The bracket set in heritage buildings plays an important role in transferring and bearing load. However, over time, damage appears in these heritage buildings, which is especially serious in bracket sets. As damage seriously affects the safety and stability of the structure, studying the mechanical properties of the damaged

This paper focuses on the estimation of the maximum impact force of dry granular flow upon a rock shed using a coupled discrete element method (DEM) and finite element method (FEM). The dry granular flow is modeled as an assembly of discrete particles, and the rock shed is modeled by applying the FEM. The coupled DEM–FEM approach calibrated with a small-scale physical experiment is used to simulate

Continuous field monitoring during drifts excavation at the Meuse/Haute-Marne Underground Research Laboratory showed anisotropic hydromechanical responses, which are mainly evidenced in: (1) pore pressure field around the drifts with zones of marked overpressure; (2) the development of a dissymmetrical fractured zone induced by the excavation. These observations suggest that in addition to the initial