Green infrastructure is a stormwater management technique that can be used to mitigate urban floods and heat islands. However, proactive monitoring and control is required to ensure its smooth operation. In particular, determining evapotranspiration, an essential process in biosphere–atmosphere interactions in cities that maintain cultivated and irrigated landscapes, is challenging. Understanding activities that govern evapotranspiration in a wide range of shallow soils is useful for planning and operation of green spaces. Recently, distributed fiber-optic sensors for monitoring civil structures and infrastructure have opened up new possibilities compared with conventional sensor systems. They operate based on the principle that strain variation in the soil is linked to environmental factors such as temperature and soil moisture changes. In this research, we examined the relationship between strain and temperature/soil moisture changes. By embedding fiber-optic strain sensors and other sensors in the soil tank, we investigated the feasibility of the sensors in a simulated soil environment.

In a bioreactor landfill, waste biodegradation, generation of gas and leachate, two-phase flow and mechanical deformation closely couple with each other. Recirculated leachate can accelerate waste biodegradation and generation of landfill gas. A significant mechanical deformation occurs due to biodegradation and suction change, and the increase in both gas pressure and leachate pressure could affect the slope stability due to a decrease in effective stress. In this paper, a full coupled hydro-mechanical-biodegradation (H-M-B) model is proposed to study the effect of the coupling processes in a bioreactor landfill on the slope stability, and a solver is implemented in OpenFOAM platform based on finite volume method. Considering the effect of volume change of solid waste, the spatial and temporal distributions of gas and leachate pressures are calculated by two-phase flow model and the corresponding slope stability is evaluated by the factor of safety calculated by the strength reduction technique method. The results characterize the effect of waste biodegradation, gas recovery and leachate recirculation on the mechanical deformation and slope stability of a bioreactor landfill, which will benefit to its design and decision-making.

The need to understand the effects of wildfire and post-fire contamination of soil and groundwater has grown as a result of the expansion of the extent and severity of wildfires around the world. In addition to their direct hazards, wildfires can also contribute to human and environmental health concerns due to secondary contamination, e.g., wildfire suppression such as aqueous film-forming foams (AFFF) can release per- and polyfluoroalkyl substances (PFAS) into the soil, which are very mobile, toxic, and persistent. Both direct seepage through the topsoil and biotransformation of fluorotelomers (FTs) determine the fate of PFAS in soils and aquifers. Research has indicated that phase partitioning behavior, such as sorption to soils and sediments, controls the fate and transport of chemicals in the environment According to various studies, the main soil or sediment characteristics that control PFAS’ sorption behavior include organic carbon (OC), pH, index cations, and ionic strength. However, neither OC, pH, nor clay-content alone could explain the sorption behavior of PFAS. More research is needed to help to understand the role of co-contaminants on the sorption behavior of PFAS, the role of surface charge on the sorption of PFAS, and on a wider range of PFAS chain compounds in the future. This paper aims to review the fate and transport of PFAS and identify the areas of research need.

Tsunami is said to be recurrent according to historical sources. Estimation of inundation area of paleotsunamis have been done by finding tsunami deposit in stratum by using sandy material in it as a clue. However, Black stream of 2011 Tohoku Earthquake left silty black tsunami deposit beyond the area where sandy material is found. It was expected that silty material as additional clue will bring better accuracy to estimation of inundation area. Formation of tsunami deposit during 2011 Tohoku Tsunami was numerically simulated. Soil core samples were obtained at Sendai Plain to find silty black tsunami deposit of AD 869 Jogan Tsunami. Silty material reached 90% of distance between the front edge of inundation area and the shorelines in the simulation result of 2011 Tohoku Tsunami. Silty black tsunami deposit of AD 869 Jogan Tsunami was found from all 18 soil core samples within inundation area of 2011 Tohoku Earthquake. Silty material was found in the simulation result at 15 out of 18 sampling points. Black tsunami deposit which contains rich amount of silty material can be another clue to estimate inundation area of paleotsunamis.

Hydrological and mechanical effects of vegetation with different root characteristics on shallow slope stability are investigated in the study. Vegetation with more roots concentrated on the soil surface has prominent effects on slope stability than uniform distributed roots. The relative importance between the hydrological and mechanical effects on slope stability mainly depends on root architecture, transpiration rate, root diameter, slope angle, and soil type. At drying conditions, mechanical effect of roots is more important in slopes with larger inclination angle, while it is the opposite for the hydrological effect. In humid areas (i.e. transpiration rate < 2 mm/day), the mechanical effect of roots dominates slope stability. After rainfall, the hydrological effect of root vanishes almost entirely inside root zone, so hence the enhancement of slope stability within root zone mainly relies on the mechanical effect of roots. The coarse-grained soil should be planted with vegetation to prevent soil shallow slope failure.

This study aims to examine the effects of layering on the seismic behavior of tailings dams. The focus is put on the spatial distribution of excess pore pressure and its variations with time during earthquake loading. In order to achieve this, dynamic centrifuge tests have been carried out for tailings dam models with thin silty layers sandwiched in sandy tailings. The experimental results demonstrate that dense sandy tailings can be contractive under cyclic loading, generating excess pore pressure. The flow of liquid upwards to the slope surface and the dissipation of excess pore pressure in the tailings can be inhibited or slowed by the overlying silty layer. The tailings covered by silty layers at shallower locations may exhibit a more pronounced increase in the ratio of excess pore pressure over initial effective vertical stress, leading to a more significant reduction in the stiffness and strength. This eventually may lead to liquefaction or failure of the slope. Those results can improve our understanding on the seismic behavior of tailings pond with thin silty layers, which is common in real mining projects.

The performance-based design of pollutant containment systems, such as landfill bottom liners and cutoff walls, requires the impact of pollutant migration on groundwater quality to be assessed. The effectiveness of pollutant containment systems is indeed demonstrated through the verification that the risk for human health and the environment due to the pollutant migration is limited to an acceptable level. This risk is quantified through the calculation of the pollutant concentration in the groundwater, which is expected to remain less than some prescribed level at a compliance point. The paper describes analytical and numerical solutions to pollutant transport, which allow the pollutant concentration in the groundwater to be calculated under different boundary conditions. Based on the results obtained from these solutions, the role played, not only by the hydraulic and diffusive properties of the containment barriers, but also by the hydrogeological features of the site (e.g. the groundwater velocity and the mechanical dispersion within the aquifer) is pointed out.

As biodegradation proceeds, municipal solid wastes (MSW) acquire pronounced soil-like properties and upon completion of the process can be used as the foundation. The solid waste massif is an inhomogeneous soil-like mass which requires non-destructive and minimally invasive methods of research. The cone penetration testing of MSW by piezocone (CPTU) in combination with the multichannel analysis of surface waves (MASW) provide extensive data about physico-mechanical properties of wastes, which are usually unavailable in traditional approaches and which can be directly used in geotechnical stability calculations of the waste massif

Thermo-osmosis is a coupled phenomenon describing the fluid flow induced by a thermal gradient. Recent studies on thermo-osmosis in clays and within the coupled thermal, hydraulic and mechanical analysis have revealed the importance of this physical processes in geo-energy and geo-environmental applications. This paper presents a series of molecular dynamics simulations of the interfacial water behaviour at the vicinity of silicate layers to quantify the nanochannel size effect on the thermo-osmotic coefficient and reveal some aspects of governing mechanisms of thermo-osmosis in nanoscale space. Our results show that the size effect emerges from the specific liquid structure controlled by the channel width. The overlapping and interfering boundary layers lead to the variations of thermo-osmotic response with the channel width. Our findings not only facilitate a basic knowledge of thermo-osmosis, but also contribute insights and methods to analyse a wider category of coupled heat and mass transfer problems in nanometric space.

Modern nondestructive techniques of wave analysis can be applied for the express preliminary geotechnical soil assessment. One of them is Multichannel Analysis of Surface Waves (MASW) which allows obtaining velocities profile of shear waves and the initial shear modulus for the upper section promptly and at minimal labor costs. But for soil deformation properties assessment the deformation modulus obtained by the direct technique of plate load test (PLT) is required. The purpose of the performed study is an assessment of the correlation between the PLT deformation modulus and the initial shear modulus obtained via MASW.

This paper presents the experimental results on the performance and use of recycled concrete aggregates derived from old concrete/construction and demolition waste and waste rubber shreds in the drainage layer of engineered landfills. About ten test columns having diameter 160 mm and height 1200 mm were set up in the laboratory. Waste rubber shreds of size range 25 mm to 75 mm and recycled concrete aggregates of size 10 mm to 20 mm were compacted either singly or in combination in the test columns, with a total bed thickness of 500 mm. The performance of the drainage layers (single or in combination) were evaluated by determining the effluent characteristics. Physico chemical parameters of effluent leachate such as pH, conductance, total dissolved solids, turbidity, hardness etc., were determined. From the study it is found that leachate sample passed through the combined drainage layer resulted in improvement of various leachate parameters compared to the test columns containing recycled concrete aggregates or waste rubber shreds media alone.

Groundwater has been used as the main source of water supply in Hanoi City for more than a century. At present, 623,500 cubic meter of groundwater have been providing per day for urban districts. In recent years, groundwater pollution due to arsenic (As), iron (Fe), ammonia (NH3), and organic matters (OM) has been reported. This paper presents a review of As contamination in groundwater in Hanoi City and investigates the adsorption capacity by autoclaved aerated concrete (AAC) as a possible adsorbent for treating As contaminated water. Results showed that a high concentration of As which was up to above 800 μg/L was found in groundwater from the Southern region of Hanoi City and was associated with high concentrations of Fe, NH3, and OM. Based on the data of As and other water quality parameters, it was suggested that the degradation of OM and ferric (Fe(III)) oxyhydroxides played a role in the mobilization of As in groundwater under reductive condition. Batch and column filtration experiments using crushed grains of AAC were carried out to evaluate the treatment performance of heavy metals including As in contaminated groundwater. Especially, the column filtration experiments gave a high efficiency of metal removal (~ 100 %), implying that AAC could be a sustainable and low-cost media to treat heavy metals in wastewater.