During dredging activities, a large amount of dredged clay slurry or lump is produced. A dumping site composed of soft clay near the water body is often used to deposit dredged soft fill. Soil-cement columns are commonly employed to treat the soft ground for this application. Under soft fill, failure of soft clay dominates the behaviour of composite ground. Hence, a soil-cement slab is needed to form

The minimum and maximum void ratios are required to establish the relative density of sandy soil. Undisturbed simple shear test specimens are often too small to provide enough material to employ the Japanese Standard JIS A 1224:2009 Test Method. An alternative test method for evaluating the dry minimum and maximum densities of soil is proposed for those cases when a test specimen does not provide enough

Rainfall infiltration is considered as one of the most significant factors triggering slope instability as a number of slope failure occurrences have been documented during or immediately after a rainfall. The rainfall-induced slope instability is governed by a complex interaction of topographical, hydrological and geological conditions of the slopes. Hence slope inclination is vital in determining

In 2005, the Japanese government launched a new nationwide early warning system for predicting debris flow and slope failure disasters based on rainfall intensity and the Soil Water Index (SWI). However, the Japanese government has not set early warning criteria in many mountain areas. In addition, the existing early warning criteria in some areas are much higher than realistic ones, and snowmelt water

Three series of sampling with thin-walled samplers, with and without inside clearance and without a piston, have been performed in a very soft organic clay deposit. The penetration and retrieval forces were measured throughout the operation, thus contributing to a clearer understanding of the sampling process. The measured forces show the importance of proper borehole cleaning conditions, and also

Bucket foundations have been increasingly used to support offshore wind turbines as alternatives to monopiles. Despite the substantial research effort on the bearing capacity and stiffness of such foundations in recent year, there is still a lack of knowledge regarding their cyclic response in saturated sand. In this paper, the multiaxial sand constitutive model Ta-Ger implemented in the finite deference

Heavy rains brought about by Typhoon Hagibis (Typhoon No. 19) in October 2019 caused great damage to the Kanto and Tohoku regions of Japan. In the Tohoku region, the rainfall was particularly high in the coastal areas of Fukushima, Miyagi, and Iwate Prefectures. In this disaster report, focus is placed on the geotechnical damage in the northern and central areas of Miyagi Prefecture. In northern Miyagi

For the predictions and simulations of energy pile behavior under a combination of thermal and mechanical loads, with a complexity of parameters describing the energy pile, the surrounding soil and their interaction, modelers may be faced with the decision of whether it is better to spend more resource on determining the appropriate value of certain model parameters with high precision or on running

Details of the failure characteristics of composite-type breakwaters reinforced by rubble have not been clarified, including the prehension of some failure modes and the conditions that cause each mode. In this study, details of the failure characteristics and a performance assessment method were studied using two approaches, namely, centrifuge model tests and a circular slip analysis. The model tests

This study investigates the ultimate bearing capacity and typical failure mechanisms of a rough strip footing constructed above an irregular cavity using the upper bound finite element limit analysis (UBFELA) method. A novel method based on the inverse discrete Fourier transform (IDFT) theory is employed to generate and quantitatively describe the irregular shape of natural cavities. Parametric studies

The maintenance of geotechnical structures, such as earth-fill dams, is required as a countermeasure against severe natural disasters, particularly earthquakes and heavy rains. The reliability-based analysis introduced here is in response to the recent demand for low-cost improvements. First, a statistical model of N values was determined from Swedish weight sounding (SWS) tests to present the spatial

Retaining wall construction often encounters narrow cohesive backfill and the traditional theories are no longer suitable. Hence, analytical solutions for active earth pressure of narrow cohesive backfill on a rigid retaining wall rotating about the bottom are proposed in this paper. The principle stress rotation caused by interface friction is also included. Through a typical FEM analysis and analytical

The paper presents an analytical solution for the vertical dynamic interaction analysis of a poroelastic soil layer and an embedded pile with the consideration of pile-soil radial deformations. The soil is treated a three-dimensional porous continuum and described by the Boer’s poroelastic model, while the pile is treated as a two-dimensional rod with both radial and vertical deformations of which

Accurate design of geotechnical structures requires precise estimation of the shear wave velocity (Vs) and the small-strain shear modulus. However, the interpretation of Vs data measured in deformed/sheared soil has not been extensively considered. This study used a triaxial apparatus equipped with planar piezoelectric transducers to monitor the evolution of Vs during triaxial compression of cohesionless

Many railway embankments sustained extensive damage due to the tsunami triggered by the 2011 off the Pacific Coast of Tohoku Earthquake, and the operations of several railway lines were suspended for an extended period of time. Numerous studies have been conducted on enhancing the earthquake resistance of embankments, and this has led to the wide application of geosynthetic-reinforced soil (GRS) structures

Use of the vertical drain method (hereinafter called “VD”) in peat ground is spreading to reduce residual settlement and increase strength by accelerating consolidation. In recent years, high embankments of nearly 10 m have been constructed on peat ground by using a combination of VDs, or plastic-board drains (PBDs) in particular, and various ground stabilization techniques. However, the conventional

The geometry of a pile can improve the bearing capacity by changing the load transfer mechanism, such as that of X-section cast-in-place concrete piles (XCC piles). Although the geometrical effects of a single pile and pile group are investigated, the geometrical effects on piled rafts are rarely understood. This paper investigates the geometrical effects on single piles and embedded piled rafts by

The two types of numerical techniques related to the Material Point Method (MPM) are reported; one is the alternative interpolation function called Arbitrary Particle Domain Interpolation (APDI), and the other is the particle-element coupled method. APDI interpolation function is one of the domain integration methods, which can consider the arbitrary shape of particle domain in MPM. The numerical domain

Side post-grouting bored-pile foundations are widely used in geotechnical engineering. However, few studies have focused on analyzing the shear behaviour of soil and concrete while considering the grouting process. A total of 48 groups of self-developed, large-scale direct shear experiments were conducted to investigate the shear behaviour of sand-concrete interface with side-grouting, focusing on

The paper revisits the notorious collapse of 18 spans of the elevated Route No. 3 of Hanshin Expressway during the 1995 Kobe earthquake. The overturned deck was monolithically connected to 3.1 m diameter piers, which failed dramatically. In stark contrast, the massive 17–pile groups survived the earthquake and are still in use, supporting the new bridge. The scope of the study is dual. Initially, the

This study presents an experimental investigation of the contribution of non-plastic fines to the development of seepage-induced internal instability and its impact on the undrained mechanical response of gap-graded sands. The purpose of the laboratory tests is to observe the internal instability of two key microstructures: (1) an underfilled microstructure in which the coarser particles control the

This paper presents a series of flume-scale tests to investigate suffusion near the tip of a cutoff wall in a double-layered alluvial foundation, where the upper and lower soil layers serve as filter and base soil, respectively. A constriction-based retention ratio was adopted to describle the particle size ratio between the two layers. The results indicate that the upper soil layer significantly influences

In the 2016 Mw 7.8 Kaikōura earthquake, widespread liquefaction occurred in the reclamations at CentrePort, Wellington (New Zealand), while less intense shaking during two earthquakes in 2013 produced only some liquefaction manifestation over isolated areas of the port. The two types of reclamations, comprised of end-dumped gravelly fills and hydraulically placed silty-sandy fills, are not well represented

This paper presents a formula to estimate the stable weight of a rubble mound for breakwaters, considering the tsunami-induced overflow and seepage flow, based on the theoretical force balance among the frictional resistance of the rubble mound, the tractive force of the water flow over the caisson to the rubble mound and the seepage force of the rubble mound through the breakwaters. A series of hydraulic

The seismic behavior of a suction bucket foundation for offshore wind turbine systems is studied using centrifuge model tests with a scaling factor of 1/100 and an effective stress analysis based on the strain space multiple mechanism model implemented in the FLIP computer code (Finite element analysis program of Liquefaction Process). The primary dimensional parameters of the prototype scale suction

The design of monopile foundations for offshore wind turbine structures is dominated by requirements resulting from serviceability and fatigue limit state. To fulfil these criteria, the load deflection-behaviour and therefore long-term accumulations of permanent deflections and rotations of the monopile foundation due to cyclic occurring wind and wave loads have to be predicted. In this paper a brief

To investigate the effect of the vertical effective and initial static shear stresses on cyclic resistance under cyclic loading with principal stress rotation, a series of cyclic direct simple shear tests were conducted on loose and dense Nakdong River sands. The results revealed that the increasing vertical effective stress (σ′v0) often decreased the cyclic resistance, and the decrease was more evident

This study investigates the suitability of the swelling and collapse theory proposed based on a constitutive virgin compression surface (VCS) developed within the modified Monash Peradeniya Kodikara (MPK) framework. The modified MPK approach incorporates net stress, void ratio, and moisture ratio as state variables to interpret the swelling-collapse behavior of unsaturated soils. The soil selected

The development of a hydro-mechanically coupled Coupled-Eulerian–Lagrangian (CEL) method and its application to the back-analysis of vibratory pile driving model tests in water-saturated sand is presented. The predicted pile penetration using this approach is in good agreement with the results of the model tests as well as with fully Lagrangian simulations. In terms of pore water pressure, however

Since the introduction of bender element tests to soil testing, the reliability of the estimated travel time has been the most serious problem. The author has previously shown a potential solution whereby removing the response of the bender element subsystem from the whole response could dramatically improve the accuracy of the travel time estimation. In order to lay the foundation for estimating the

Jacket structures mounted on suction buckets carry potential as cost-efficient foundations for next-generation 10 MW+ offshore wind turbines located in transitional water depths. Given this foundation method, resistance to overturning moment relies mainly on the axial response of the buckets. In practice, suction bucket foundations can be modelled as “Beams on Non-Linear Winkler Foundation” where soil

Modeling an embankment by subjecting it to different upstream conditions in a centrifuge is challenging. However, the response of an embankment to shaking under different upstream conditions needs to be studied to ensure that the necessary precautions are taken during its construction and maintenance. Herein, the influence of different upstream conditions and embankment densities are investigated.

This paper investigates the frequency-dependent pile-head impedance characteristics of a model soil-pile foundation system under large amplitude loads, inducing soil yielding. Testing was conducted on a scaled single pile embedded in sand under a 1g condition. A laminar shear box mounted on a unidirectional shaking table was used to house the soil-pile foundation system. Quasi-static loads and dynamic

The paper addresses the reliability change of a road bridge pile foundation due to the unpredictable increase of settlements in time. The analysis is based on the Rędziński Bridge in Wrocław, Poland, its design assumptions, and monitoring results. The bridge foundation rests on a multi-layered subsoil assumed random. The Finite Element model of the subgrade is generated in ZSoil® software. To simplify

Monopiles and gravity base foundations (GBF) are two of the most commonly used foundations for offshore wind turbines. As resonance can cause damage and even failure of wind turbines, understanding the difference between the dynamic responses of monopiles and GBFs under free vibration is important. However there is little experimental data regarding their natural frequency, especially from model tests

The railway embankment applied to high-speed railways is required to have high performance in terms of strength and deformation characteristics. Especially in the case of railway embankments that support slab tracks, the allowable settlement is very small. There are two technical challenges in constructing high-speed rail embankments to support slab tracks in India. The first challenge is dealing with

There was a shallow earthquake in the Central Sulawesi province of Sulawesi island of Indonesia with a moment magnitude (Mw) 7.5 on 28th September 2018 at 18:02:44 local time. The event was preceded by major foreshocks and followed by aftershocks of significant magnitude. The epicenter of the main shock was in the Donggala regency of Minahasa peninsula of Central Sulawesi, approximately 70 km from

This paper discusses the instability of an offshore monopile in association with wave-induced liquefaction of sand beds. Centrifuge wave tests in a drum channel were performed with viscous scaling introduced such that the time-scaling laws for fluid wave propagation and consolidation of the soil were matched. The relationships between liquefaction and the start and development of monopile instability

The Mietsu Naval Facility (MNF) was established as a Western-style military facility by the Saga Clan in 1858. The aim of the present study was to examine the purpose and installation method of cedar logs preserved in the Small Boat Dock (SBD) section of the MNF. In order to restore the scale and shape of the superstructure at the SBD to those at the time of its construction, it was necessary to determine

A new strength estimation equation for cement-treated clay is proposed for marine clay with wide ranges of sand and initial water contents. The proposed equation can determine the strength of cement-treated soil by using two parameters, the ratio of the cement content to the mass of fine particles in the soil and the volumetric solid ratio excluding sand, where sand is defined as particles greater

Excavated soils and rocks, containing toxic metals and/or metalloids from geogenic sources, are usually generated in huge volumes at construction sites. And the post-excavation leaching of these toxic metals and/or metalloids with low concentrations, but higher than the environmental standards, is a major environmental concern. A sorption layer method was developed as a cost-effective countermeasure

A method is presented for using DEM to find the pore pressure, total stress, and effective stress within a granular assembly during either undrained or drained conditions, by using poroelastic principles to directly determine the pore fluid pressure. The paper considers both the saturated and quasi-saturated conditions, the latter meaning a slightly unsaturated granular material, in which isolated

This paper establishes an analytical correlation between factor of safety (FS) and reliability index β values commonly used in the design of drilled shafts in sand. This is achieved through fragility analysis of unit shaft and base resistances, calculated using finite element analysis-based capacity calculation equations, for drilled shafts. Analytical fragility curves are developed for allowable unit

Model tests are carried out in this research to investigate the dynamic behavior of multi-section cut-and-cover subway tunnels in the transverse direction by seismic motion, which has not been fully investigated up to now. Multi-section model and general single-track box-section model tunnels are installed in a soil vessel, and it is found that the sectional force corresponds to that obtained in the

Triaxial tests and numerical simulations were conducted to determine the water absorption compression of unsaturated soil. In the triaxial tests, unsaturated silt specimens under the same initial condition were prepared and the processes of different suction reduction, isotropic consolidation, and exhausted-drained shearing were applied to the specimens. The numerical simulations used a soil-water-air

Soil arching is an important phenomenon in the discussion on soil-structure interactions. Soil arching can increase the stresses exerted on a buried structure, while the absence of soil arching often results in differential surface settlement due to the difference in stiffness between the structure and the surrounding subsoil. In this investigation, model tests were conducted to relate the particle-scale

The ‘press-in’ method is a piling technique by which a pile is installed with a static jacking force while a reaction force is obtained from previously installed piles. The applicable ground conditions for this method have been significantly expanded by the ‘Rotary Cutting Press-in (RCP)’ method, whereby a vertical jacking force and a torque are applied simultaneously onto a pile with cutting teeth

On March 11, 2011, a large earthquake of Mw 9.0 shook north-eastern Japan and caused severe liquefaction-induced damage over a wide area of reclaimed lands along the coast of Tokyo Bay. Although regional mapping of the liquefaction hazard had been performed in many automounts bodies in Japan, it seems that the maps were not effectively used on all fronts of disaster-prevention management, because the

The unsaturated hydraulic conductivity function is one of the keys to solve unsaturated seepage issues, and it is difficult to be obtained via the laboratory test considering the time involved. In this study, a series of laboratory tests, include capillary rise test and downward infiltration test, were conducted to obtain the unsaturated hydraulic conductivity function of six kinds of soils varies

In engineering applications, narrow backfills are often squeezed by retaining walls. Insufficient information is available with respect to the passive earth pressure, whereas the active earth pressure of narrow backfills against retaining walls has been considerably investigated. In this study, the passive failure mechanism of a narrow cohesionless backfill under translation mode has been investigated

The objective of this study was to evaluate the effects of geostatic stresses on the compressibility and strength development of submerged geopolymer stabilized columns. In this research study, modified 1D consolidation cells were developed to replicate deep mixed columns in the field when subjected to varying stresses at various depths. Various combinations of fly ash (FA) and slag (S) precursors

The micromechanical behaviour of two sand–rubber mixture samples (i.e., a glass bead–rubber mixture sample (GB–R) and a Leighton Buzzard sand–rubber mixture sample (LBS–R)) under triaxial compression is investigated using X-ray micro-CT (μCT). Both samples contain sand and rubber grains with similar size and have a rubber content of 30% by mass. The results are compared to those of two pure sand samples

Cohesionless granular soils display stiffness anisotropy, and accurately characterizing it is essential for numerous geotechnical applications. The inherent anisotropic behaviour of geomaterials is not comprehensively understood; hence, research on the development of novel geophysical testing methods for assessing multidirectional stiffness is important. This contribution presents an innovative arrangement

The input parameters for the hardening law for the elasto-plastic constitutive model of unsaturated soils are generally fitting parameters that control the degree of hardening response and cannot easily be determined without the results of experimental tests in which the changes in suction, water content, and volume are measured or controlled. However, it is next to impossible to complete such precise

Extensive particle fracture has been noticed in projectile penetration tests. However current models for predicting projectile penetration depths do not consider particle fracture. Therefore, in order to understand the role of particle shape on single grain strength and the subsequent comminution process, single grain crushing tests on sand grains of different shapes and sizes were performed. High-resolution

Swelling deformation tests of GaoMiaoZi (GMZ01) bentonite were performed at 25, 40 60, and 90 °C in distilled water. Experimental results suggested that the maximum swelling strain of GMZ01 bentonite increased with temperature, due to the osmotic swelling dominated the swelling. The em − σv relation for compacted bentonite at a same temperature can be expressed as em=KσvD-3 (em is montmorillonite void

Piles with enlarged base have been widely employed in the civil and coastal engineering due to its high resistance to uplift. Many researchers have investigated the bearing capacity of enlarged base piles in case of small strains, but the investigations of enlarged base piles with variable geometries and large deformations are very limited. In this work, Material Point Method (MPM) is adopted to investigate

This report describes the damage and ground movements observed in the residential area of Satozuka 1-Jo, Sapporo, Japan during the 2018 Eastern Iburi Earthquake as triggered by the liquefaction of pumice sand with which a valley had been filled. The geographical setting and the on-ground and aerial reconnaissance and soil characterization results are reported, leading to a possible scenario of the

In the present note, constitutive equations for air-water-solid three-phase porous materials were formulated considering thermodynamics in the context of continuum mechanics. In the formulation, the complementary energy function was used and the internal variable was adopted that manifests the inelastic strain. Then, a linear three-phase elastic model was analyzed in detail and the material parameters

The bentonite and ocean-floor clay used in hydraulic barriers for on-land and ocean waste disposal sites, respectively, act as the last defense against environmental pollution, and therefore must have high chemical resistivity and long-term stability. The primary factors that determine the hydraulic conductivity of bentonite and ocean-floor clay are the polarity and functional groups of their organic