The design and performance of the 174-m high Quxue asphalt-core rockfill dam in Sichuan Province, China, are presented. An extensive field monitoring program was implemented. During construction, the asphalt core settled more than the adjacent transition zones, but no more than 20 mm due to strong interlocking with the coarser gravel particles in the transition zones. The lateral displacements of the

Problems of ultra-soft soils, with the characteristics of high water content and very low strength, have been gradually distinguished from those of typical soft soils in recent years to address the new requirements of ocean geotechnical engineering, such as the improvement of dredged fills and hazard assessment of submarine landslides. Focusing on effects of high water content and different shear strain

This paper presents an analytical approach for predicting the nonlinear load-displacement behaviour of pile groups consisting of displacement piles in normally consolidated and lightly overconsolidated clayey soils. The effects of squeezing and remolding on the soil around the piles caused by pile installation are reflected by the soil strength and shear modulus. The nonlinear load-displacement behaviour

Since the mechanical failure of granular soils is the macro-manifestation of complex internal particle interactions, studying this relevant issue from micro-scale perspective is of fundamental importance. Acoustic Emission (AE) has become a promising approach for this purpose; however, its synthetic and validating study on granular soils with various ground conditions is far from substantive. In an

The present study considers the influence of inclined and eccentric loading on the bearing capacity of a strip footing placed on the reinforced cohesionless soil slope by using lower bound finite element limit analysis technique. The effects of other parameters such as soil friction angle, embedment depth of reinforcement layer below the footing, interface friction angle between soil and reinforcement

A number of landslides occur in the soil slopes overlying bedrock due to excavation. However, the excavation-induced deformation and failure behavior and the coupling influential mechanism of the bedrock and excavation have not been clearly elucidated, although they are essential for the stability analysis of slopes overlying bedrock under excavation conditions. In this paper, a series of centrifuge

Soil particle size distribution (PSD) is critical for assessing the potential for internal instability of sand–gravel soils, mainly because particle migration in sand–gravel soils owing to seepage forces affects almost all soil hydraulic properties during internal erosion processes. Therefore, a reliable PSD analysis is essential for revealing the mechanism of particle migration and internal instability

An image-based measurement system was developed to evaluate the induced local deformations of saturated sand specimens in undrained torsional shear tests. The images of specimens taken by a camera in front of a pressure chamber were noticeably distorted. To correct the errors caused by the curvature of the specimens and by the refraction of rays traveling through water, acrylic resin, and the atmosphere

Natural disasters like earthquakes and heavy rainfall events induce slope failures and other disasters. Proper determination of the water retention properties of porous mediums is necessary. The conventional Soil Water Characteristics Curve (SWCC) determination techniques are limited due to their complexity and lengthy time required. A highly accurate simple remolded and undisturbed samples SWCC determination

In the design and construction of structures, information on the SPT N-values and the undrained shear strength is very important for investigating problems related to stability, deformation, etc. Since the shear wave velocity (S-wave velocity) is correlated with these properties, geophysical exploration methods, such as surface wave methods, which can estimate the properties densely over a wide area

Free Fall Penetrometer (FFP) testing consist of a torpedo-shaped body freefalling into a soil target. The use of this type of device is becoming popular for the characterization of shallow sediments in near-shore and off-shore environments because it is a fast, versatile, and non-expensive test capable of recording acceleration and pore pressures. In recent years, the data analysis advanced considerably

Pavement structures constructed on the expansive soil subgrade experience a higher upward pressure compared to any other subgrade material. The upward pressure is caused due to high swelling and shrinkage characteristics of expansive clay soil. The present study has investigated and identified the mechanisms by which a remolded expansive soil can be modified to reduce the upward pressure and swelling

A new method to model the abrasion of granular particles using the discrete element method is demonstrated in this paper. This new, simple method is based on a classical theory of abrasive wear, relating the volume of solid lost to the frictional work at particle contacts. The modelling technique is demonstrated in simulations of railway ballast using realistically-shaped particles, which are compared

On 28th September 2018, an earthquake of Mw 7.5 struck Donggala Regency, Central Sulawesi, Indonesia, resulting in a catastrophic disaster and a large numbers of casualties. In this report, the results of the preliminary field investigations carried out by the authors’ team are summarized. The earthquake caused four major long-distance flow-slides on very gentle slopes of approximately 1–5% in and

A study was conducted to stabilize An Nafud desert sand against wind-induced erosion employing enzyme-induced carbonate precipitation (EICP) assisted by a sodium alginate (SA) biopolymer. Biopolymers occur naturally in brown seaweed, are inexpensive, and are used extensively in the food, textile, and paper industries as thickeners and emulsifiers. A wind tunnel experiment was conducted to evaluate

Lacustrine soils from the former Texcoco Lake within the Basin of Mexico, some 14 km north of Mexico City, have unique geotechnical properties. These materials have been thoroughly studied in the past, and yet, very few investigations have addressed the issue of the anisotropy of their shear stiffness modulus at very small strain levels (G0). Stiffness anisotropy, even at very small deformations, may

The accurate determination of resilient modulus (Mr) of pavement subgrade soils is an important factor for the successful design of pavement system. The important soil property Mr is complex in nature as it is dependent on several influential factors, such as soil physical properties, applied stress conditions, and environmental conditions. The aim of this study is to explore the potential of an evolutionary

Spudcan retrieval from clay soils remains a major concern offshore as the extraction force required to overcome suction and soil resistance often exceeds the pulling capacity available on the mobile jack-up, causing extensive delays. Although methods to calculate extraction resistance have been recently suggested for seabeds of pure clay, to date there is no guidance available for the commonly encountered

The initial infiltration of ground water into tunnels excavated in soft clayey soils triggers the consolidation of the surrounding soil and imposes an extra load on the linings. This extra load may open the joints between rings and segments or intensify the deterioration of the joints. Relative soil-lining permeability, an important factor in the long-term behavior of tunnels, mainly depends on the

This paper presents an experimental study on the effect of polypropylene fibres on the yielding behaviour of cement-admixed soft marine clay. A range of mix ratios is investigated, with the cement content spanning from 20% to 100%. The unconfined compression strength is first examined, followed by isotropic compression and subsequently shearing in triaxial stress conditions. These experimental results

Soil properties (or parameters herein) vary randomly in space because of different depositional conditions. The knowledge of the spatial variability characteristics of unsaturated soils can be critical to the reliability assessment of geological and geotechnical engineering problems such as the stability analysis of unsaturated soil slopes and the seepage analysis of earth dams. To investigate the

Shaft resistance is the major source of bearing capacity and has a critical effect on settlement of prebored and precast pile (PPP). In this paper, the load-transfer behavior and shaft resistance of steel pipe PPP was observed based on real scale pile loading tests. The main focus was on determining the load transfer mechanism and establishing a framework on shaft behavior of steel pipe PPPs. 10 cases

This study investigated the soil adsorption characteristics against gaseous mercury. A method for the adsorption tests using gaseous mercury was established, and the distribution coefficients for silica sand, decomposed granite soil, mordenite, and calcium bentonite were evaluated. Glass vials with polytetrafluoroethylene (PTFE) plugs were suitable for the adsorption tests as gaseous mercury did not

The deterioration of compacted bentonite-sand mixtures (CBSMs) after suffering desiccation increases the hydraulic conductivity of clay barriers, posing risks to the environment. This work compressed bentonite-sand mixtures (BSMs) to various dry densities in order to conduct the free-drying tests, focusing on the evaporation and shrinkage processes. The compaction constrained the permeability of the

Discrete element method simulations are used to investigate the effects of particle shape on the plastic behaviour of sand. This is achieved by using four different shapes of crushable particles. The behaviours of the different particles when subjected to isotropic compression, triaxial shearing, and a range of stress path tests are compared, revealing the important role of particle shape on key aspects

This paper presents the effects of inherent anisotropy on the shear strength and shear modulus of both saturated and unsaturated sands. Several triaxial compression tests were performed using Toyoura sand with different contents of mica: 0%, 1%, 2.5%, 5%, and 10%. Specimens with various deposition angles α were prepared using the air pluviation (AP) and dry vibration (DV) methods. The shear strength

This paper presents a field study on the compressive bearing capacity of pre-bored grouted planted (PGP) pile and bored pile embedded in deep soft clay. The test site consisted of many concrete square piles which were used for the foundation of the old structures. The PGP pile and bored pile were considered as the two suitable pile types in this test site. The test results show that: the compressive

Intrinsic flaws are an important factor affecting particle strength and breakage behavior and are closely related to the macroscopic behavior of granular soils, e.g., packing characteristics, strength, deformation, localization and failure behaviors, etc. In this paper, a novel DEM modeling approach for investigating the role of flaws on the particle crushing behavior is proposed. The idea is to use

Although several empirical and analytical models are available to predict the threshold fines content (fthr) for sand-silt mixtures, none of them considers the combined effects of particle shape and size. In view of this, the current paper proposes a method to estimate the threshold fines content and the minimum void ratios for sand-silt mixtures at various contents of non-cohesive fines incorporating

A numerical approach, the Hyperstatic Reaction Method (HRM), is presented in this paper to study the behavior of two kinds of U-shaped tunnel linings (with and without an inverted arch). The developed numerical HRM model is validated by a comparison with the results obtained from finite difference numerical models using FLAC3D. The results of this paper show that the behavior of U-shaped tunnel supports

This paper presents a probabilistic limit state framework for the evaluation of the base resistance of drilled shafts in soft rock. In situ load tests and the Griffith fracture theory are used to evaluate the mode of failure for the rock mass under the drilled shaft base. The base resistance or the limit state in the context of this paper is defined by the contact pressure at which load induced vertical

This paper presents a hybrid numerical tool for nonlinear piled rafts analysis. The nonlinear pile behavior is represented by a hyperbolic function, which intends to simulate the variation in pile stiffness during loading. As the nonlinear behavior of piles is restricted to a very thin zone next to the pile interface, only the linear elastic effects are considered in the interaction factors between

Sand–concrete interface direct shear tests were used to investigate the effects of surface roughness, surface waviness, mean sand diameter and relative density on interface strength and behavior under different confinement conditions. Extreme concrete surface textures, including smooth, rough and rough–wavy textures, were reproduced. Surface plowing was assessed via image analysis, laser scanning and

In the present study, the micromechanical behaviour at the interfaces of sand grains coated with kaolinite powder is examined. Two different classes of coated grains were produced, one with lighter coating and one with heavier coating. The interface micromechanical experiments were conducted on pairs of grains and the emphasis was placed on the normal and tangential load-displacement relationships

The excavation of a new tunnel above an existing shield tunnel at close proximity may cause a series of adverse impacts on the underlying tunnel. Thus, a reasonable assessment of the existing shield tunnel’s responses to overcrossing tunnelling is crucial to ensuring the safety and serviceability of the existing shield tunnel. In this study, a simplified nonlinear analytical method is proposed to rapidly

This study presents the results of full-scale tests and three-dimensional finite element analyses of deep cement mixing (DCM) and stiffened deep cement mixing (SDCM) columns under lateral loads and DCM and SDCM walls under deep excavation in soft clay. The DCM walls used in this study comprised one, two and three rows of DCM columns, whereas the SDCM walls consisted of only one row of DCM columns with

The mechanical characteristics of ultra-high asphalt concrete core rockfill dams (UACCRDs) at different periods is investigated via Rankine’s earth pressure theory, and a shear safety control standard for UACCRDs is proposed. The reasonable material parameters of the asphalt concrete core (ACC) and transition material that independently and comprehensively satisfy the shear safety control standard

A method for evaluating the liquefaction probability of an earth-fill dam over the next 50 years is presented through the use of a geostatistical method for the measured values from cone penetration tests (CPTs). In particular, this paper discusses a new procedure for evaluating the liquefaction probability based on CPTs. Although the fines content, Fc, and the N-value are required in the Japanese

The minimum void ratio is an index widely used to indicate the contraction characteristics and the densest state of soils. The minimum void ratio obtained by the traditional test method has been utilized to represent the density of soils irrespective of their fines content despite the restriction (FC ≤ 5%). By considering the effect of the blow count, pore water, and their primary properties, the applicability

Recent earthquakes in New Zealand and Japan indicate that evaluating the liquefaction potential of silty sands remains an area of difficulty and uncertainty in geotechnical engineering. This paper presents a comprehensive experimental study along with analysis and interpretation in the framework of critical state soil mechanics, with the aim to address the complicated effects of fines. Two series of

During the Great East Japan Earthquake and Tsunami of 2011, enormous coastal levees collapsed as a result of tsunami overflows. Concrete-covered levees, where concrete blocks are used to protect levees made of soil, showed a specific failure mode in which back slope blocks and internal soils were dislodged. Although several hydraulic experiments have been conducted in an attempt to understand the failure

Dynamic centrifuge model tests and associated analyses are carried out to develop a procedure for simulating the slope failure process during earthquakes and to evaluate the force of a sliding soil mass impacting a structure. This impact force is successfully measured in the dynamic centrifuge model tests using a slope height of 50 m in the prototype scale. The results of a pseudo-static limit equilibrium

Geosynthetic clay liners (GCLs), used to repair small earth dams, are typically installed with the GCL panel placed parallel to the upstream slope of the dam or on the surface of benches cut into the upstream side of the earth dam fill. While the former requires less earthwork, leading to a more cost-effective and rapid construction, it can potentially introduce a plane of weakness if the interface

This paper presents a new method for analyzing the nonlinear response of a single, vertical pile with the circular cross-section under torque in layered soils. The nonlinear stress-strain relationships of both soil-pile interface and soil are approximated by the hyperbolic model, whereas the pile material is elastic. The torsional spring stiffness of the soil-pile interface and the soil are determined

Accurate predictions of the mechanical response of root-soil systems are required for assessing and reducing the risk of landslides, surface erosions, and lodging. The present paper proposes the use of the node-to-segment (NTS) approach with the finite element method for predicting contact phenomena between roots and soils, such as collision, sliding, and separation. To obtain reliable predictions

This paper presents the results of a laboratory investigation into the performance of geosynthetic-encased stone column-improved (GESC-improved) soft clay under vertical cyclic loading. A reduced-scale model is adopted to perform a series of tests considering the principal parameters, such as the cyclic loading characteristics, including the loading frequency and amplitude, and the encasement length

The seismic bearing capacity of shallow strip foundations in the vicinity of slopes was investigated by the use of the lower bound limit analysis in conjunction with the finite element method and the linear programming technique. The combination of the most probable failure modes including slope instability and ultimate bearing capacity makes the problem difficult to solve by conventional approximate

Geopolymer is a cementitious material that can replace ordinary Portland cement in several geotechnical engineering applications, such as soil stabilization, with the advantages of much lower harmful emissions and energy consumption. This paper presents a rigorous evaluation of the geo-mechanical behavior of different types of clay soils treated with geopolymer, including the influence of soil characteristics

In this paper, a rational method for estimating the unit weight of cement-treated clay is proposed, which takes into account the relationship between the various phases and changes in these phases during curing. The simplest unit weight estimate is the unreacted unit weight which may be used as a lower-bound estimate of the cured unit weight. More accurate estimates of the unit-weight are possible

This study investigates different methods for generating non-uniform support acceleration at actual topographic sites. The factors affecting the non-uniform excitation of a topographic site include the time delay between the arrival times of incident waves at different soil depths, causing a phase difference, and the coherence function. The existing coherence models are based on data recorded on flat

The ability of hydraulic pile driving hammers to overcome energy losses during freefall enables a greater proportion of the impact energy to be transferred to the pile than is possible with diesel hammers. This percentage, termed the energy transfer ratio, is not routinely measured in practice however, and there is an element of uncertainty regarding appropriate energy transfer ratios to adopt in driveability

Multivariate information of soil parameters is quite important for the design and risk assessment of geotechnical engineering problems. It is necessary to have an accurate and realistic statistical multivariate model for representing the soil properties and thus evaluating the soil conditions. Thus, advanced multivariate modeling of soil parameters could help to improve the geotechnical engineering

In geotechnical engineering, the stability of rigid footings under eccentric vertical loads is an important issue. This is because the number of superstructure buildings has increased and the situation of structures being subjected to eccentric vertical loading is occurring more and more frequently. In this study, focus is placed on the ultimate bearing capacity of a footing against the eccentric load

The flow and transport behaviors in porous media are closely linked to the structure and morphology of the pore space. A fundamental objective of most studies of porous media is to link the pore structure to the hydraulic functions, such as the permeability, capillary pressure and diffusivity, which are necessary for engineering applications. In this paper, an attempt is made to build a direct link

The original stress-fractional plasticity approach was developed for the axisymmetric stress state. However, it cannot accurately capture the stress-strain behaviour, e.g., quasi-steady state flow, temporary stress peak and state-dependent dilatancy of soils under different loading conditions. In this study, a modified fractional-order plasticity model for soils under the general stress state is developed

It has been reported that soils belonging to slope grounds show different types of liquefaction behavior than those belonging to horizontal grounds. Some research has also revealed that liquefaction histories can significantly affect the shear behavior of sandy soils. However, the combined effects of the slope angle and the magnitude of past shear histories on the liquefaction properties of soils have

The current research is focused on the static liquefaction and effective stress path characteristics of soils of the high seismicity Kutch region, India. In previous studies, the effects of the fines content and the plasticity of the fines on the undrained behavior were explored in a controlled and systematic manner with either non-plastic or plastic fines added to standard or river sands. The undrained

The mineral alteration and microstructure evolution of compacted GMZ bentonite was investigated during the long-term in the Beishan area, a candidate for a high-level radioactive waste repository in China. The compacted GMZ bentonite samples at initial dry densities of 1.5 and 1.7 Mg/m3 were infiltrated by synthetic Beishan Site Water (BSW) and two synthetic cement solutions (Young Cement Water -YCW

The last decade has seen an increasing amount of research on so called “transitional” soils that are characterised by incomplete convergence to unique normal compression lines and/or critical state lines in simple laboratory tests. This topic has often provoked reaction, perhaps because some have seen it as a challenge to critical state frameworks of soil behaviour. A particular issue is whether incomplete