Life Cycle Assessment Applied to Railway Infrastructure: A Proposed Method

Based on mitigation strategies for the rational use of resources and conscious consumption of inputs, it is important to develop tools that allow the measurement of environmental impacts and greenhouse gas emissions, for better decision-making in the planning of railway infrastructure activities. Therefore, this article presents a method for evaluating railway infrastructure projects, having as a parameter the potential impact of global warming when different materials are used in the sub-ballast, to improve the support capacity of the railway pavement. As a technical criterion for evaluation, the mechanical behavior of the subgrade was considered in a condition of moisture above the optimal level, with a sub-ballast composed of sandy material as a baseline for comparison. The results, considering the environmental impact, clearly indicated that the use of a soil-cement mixture in the sub-ballast was the best option. Furthermore, even in the face of more frequent renovation of the permanent way, the reference scenario was more attractive than those with use of a combination of soil-emulsion and hot mix asphalt.

Pendekatan Hidrogeomorfologi Dan Pendugaan Geolistrik Untuk Identifikasi Potensi Airtanah Di Jedong Malang

This study aims to identify the potential groundwater in Jedong, Malang, East Java. The hydrogeomorphological approach is a suitable approach to describe the relationship between hydrological and geomorphological processes on and below the earth's surface. The survey of geoelectricity complements the hydrogeomorphological approach. It will give a better description of the groundwater conditions below the earth's surface. Based on the research, there are 2 hydrogeomorphological units in the study area, which are: Volcanic Foot Valley Unit and Volcanic Foot Ridge Unit. The best groundwater potential is in Volcanic Foot Valley Hydrogeomorphological unit, namely Awar-awar Valley and Cokro Valley. The valleys are dominated by gully erosion and landslides. They have surface deposits up to a depth of 7 meters, and lots of outcrops of breccia, pumice, and andesite boulders. The valley’s springs discharge between 56 - 198 m3/day. The average infiltration rate in the valley is 1776 mm / hour, with sandy soil material. The best aquifer consisting of sandy material is more than 10 meters in depth, based on the geoelectrical survey. Water in the aquiclude layer, cannot be exploited because it is breccia and tuff material. The Sawah valley cannot be exploited further because the groundwater potential is very low. This can be identified by the thick water outflow seepage. In the Volcanic Foot Ridge Hydrogeomorphological unit, the groundwater potential is also very small. Hydrogeomorphically, water will flow down the slope to the valley. It will reduce the infiltration rate. In general, the ridge area is only used for settlement, while the slopes are used for dryland agriculture. The geoelectric analysis results show that the groundwater potential is at a depth of more than 45 meters. This research’s results show that the combination of the hydrogeomorphological approach and the geoelectric use will provide a better description of the potential groundwater.

Influence of Storm Conditions on Changes in the Granulometric Composition of Bottom Sediments in the Coastal Zone of the Western Crimea

The aim of this work is to study the dynamics of bottom sediments granulometric fractions in the Kalamitsky Gulf coastal zone near the Lake Sakskoe bay-bar under influence of storm surge based on the XBeach numerical morphodynamic model. A series of numerical experiments has been carried out, in which the parameters of waves at the seaward boundary of the computational domain changed in time, simulating the passage of a cyclonic atmospheric anomaly over the investigated region. The initial distribution of the sediment volume concentrations in different parts of the underwater coastal slope profile was set based on the results of field observations. The duration of model calculations was 24 h. The quantitative characteristics of the spatial distribution of various bottom sediments fractions, sediments median diameter and values of bottom deformations were obtained. It has been established that the main morphodynamic changes occurs in the area 0–120 m from the shoreline and are limited by the 3.5 m isobath. It was noted that the maximum changes in the relief of the coastal zone and the upper section of the underwater coastal slope occur during the development and attenuation phases of a storm. In the same time intervals an intensive redistribution of sandy material is observed. It has been established that, with a change in the parameters of wind waves in time at the seaward boundary, the scales of sand material redistribution and deformations of the coastal zone are higher than in the experiment when the direction of the waves does not change with time at the seaward boundary of the computational domain.

A Parametric Study of Piled Raft Foundation in Clay Subjected to Concentrated Loading

The use of piled raft foundation in building and infrastructure constructions is increasingly popular because of its effectiveness in reducing overall and differential settlements. Parameters influencing the performance of the piled raft foundation need to be comprehended in order to optimize the design of the piled raft system. Most of the current available literature focused on the piled raft foundation subjected to a uniform distributed load in sandy material. This parametric study aims to provide insights into the performance of the piled raft foundations subjected to concentrated loading in clay. A series of 2D finite element analyses were performed to investigate the influencing parameters affecting the load distribution and settlement behaviour of the piled raft. The results suggested that increases in both pile length and raft thickness, as well as a decrease in pile spacing would reduce the differential settlement of the piled raft. Comparatively, raft thickness was the most significant controlling parameter affecting the differential settlement. The study also revealed the importance of placing the pile nearer to the location of concentrated load as it would yield a more uniform load distribution, and hence a lower differential settlement.

Mapping the Pollution Plume Using the Self-Potential Geophysical Method: Case of Oum Azza Landfill, Rabat, Morocco

The main landfill in the city of Rabat (Morocco) is based on sandy material containing the shallow Mio-Pliocene aquifer. The presence of a pollution plume is likely, but its extent is not known. Measurements of spontaneous potential (SP) from the soil surface were cross-referenced with direct measurements of the water table and leachates (pH, redox potential, electrical conductivity) according to the available accesses, as well as with an analysis of the landscape and the water table flows. With a few precautions during data acquisition on this resistive terrain, the results made it possible to separate the electrokinetic (~30%) and electrochemical (~70%) components responsible for the range of potentials observed (70 mV). The plume is detected in the hydrogeological downstream of the discharge, but is captured by the natural drainage network and does not extend further under the hills.

Criteria for petroleum potential and forecast of oil and gas prospective zones in the Achimov deposits of the Gydan Peninsula

The structure and seismogeological characteristics of the Achimov strata of the Gydan Peninsula are considered. Geological and geophysical criteria for the regional forecast of oil and gas potential, taking into account the clinoform structure of the Berriasian-Lower Aptian deposits, are proposed. Based on the interpretation of drilling data and 2D seismic exploration, predictive maps of the thickness of sand bodies were constructed, depocenters of accumulation of sandy material were mapped. Seismostratigraphic studies, which are based on a comprehensive analysis of the wave pattern of time seismic sections, dynamic and seismic facies analyzes, as well as paleotectonic and paleogeomorphological reconstructions, made it possible to identify the Salmanovskaya and Yuzhno-Gydanskaya oil and gas zones in the Achimov strata of the Gydan Peninsula.

THE MODERN MORPHODYNAMICS IN THE QUARRIES OF LVIV AND ITS SUBURBS

The seven big quarries have been explored in and around Lviv. All quarries are sandy and most of them are inactive now. There are 3 quarries located directly in the city: two – within the Znesinnia Regional Landscape Park (western and eastern) and Kryvchytskyi. The four quarries are located in the southeastern outskirt of Lviv within the Davydivskyi Chain near the villages of Davydiv (3 quarries) and Vynnychky. The processes of water erosion (sheet, rill and gully erosion), suffosion, falls, scree formation processes, slides, physical and chemical weathering are widespread in the explored quarries. The specific azonal processes such as aeolian processes (deflation and accumulation of sandy material) and formation of takyrs are also common. The most common are water erosion processes (sheet, rill and gully erosion). They are present in almost all quarries (except of Western Znesinskyi and Kryvchytskyi Quarries). These processes occur in the lower parts of quarry benches and on the slopes of dumps. They are represented by small and medium-sized erosive pre-rills and rills (width 5–30 cm, depth up to 45 cm), small gullies (depth up to 2.2 m), debris cones, deluvial cones. The sheet, rill and gully erosions mainly occur together. The suffosion processes develop in the sandy-loam deposits with low density (the Davydivskyi Quarry № 2, the Vynnychkivskyi Quarry). The result of these processes is the formation of suffosion sinkholes (35–60 cm in diameter) and suffosion “wells”. The processes of rockfalls are locally widespread on steep denudation benches of quarries, where beds of limestone or sandstone are cropped out (the Davydivskyi Quarry № 1, № 3). The scree formation processes are also common in gravitational processes and mainly occur in sandy deposits and are represented by scree cones. Slides occur rarely having small main bodies and are located on the quarry walls and dump slopes. A special type of processes in the studied quarries is the formation of takyrs, which occurs in closed watered areas of the pit floors. After the takyrs dry up, the so-called "desert papyrus" is created. Key words: modern morphodynamics, quarry, water erosion processes, falls, scree formation processes, Lviv.

Geophysical characterization and hydraulic properties of unconsolidated floodplain aquifer system in Wamako area, Sokoto State, north-western Nigeria

The subsurface internal geometry of Rima River floodplain located in north-western area of Nigeria was investigated using 2D resistivity imaging, vertical electrical sounding (VES) and laboratory analyses. Four profiles were acquired using Wenner array. The apparent resistivity computed was used to produce 2D electrical resistivity pseudosections using RES2DINV software. A total of nine VESs were acquired along the four profiles in the study area with AB/2 of 1 to 100 m. Quantitative interpretation of VES curves was done by partial curve matching and computer-assisted 1D forward modelling with the WinResist version 1.0 software. Five pits were dug along the profiles to confirm the interpreted results from the geophysical surveys. Soil samples were collected from the pits at various depths, and hydraulic conductivity (K) was estimated in the laboratory using the constant head permeability test following standard procedure. Interpretations of electrical resistivity technique show three to four subsurface layers including topsoil, sandy material and clay/saturated clayey materials. The sandy material is believed to be saturated with water with appreciable amount of porosity and permeability. This layer was further confirmed by pitting around the study area. From the laboratory and empirical estimation of K, it was discovered that the K value ranges from 10−2 to 10−6 m/s, which shows that the sample is clean sand which is moderately to highly permeable. The grain size analysis revealed from the cumulative plot that the sample falls predominantly within medium-sized sand, which makes the study area a good aquifer system.