Search results for "Geotechnical engineering"
showing 10 items of 489 documents
ERT and IPT surveys to check the integrity of the geomembrane in the landfill of Bellolampo (Palermo, Italy)
2016
In landfills, changes in resistivity and chargeability can be related to the characteristics of the waste and they can be abrupt and considerable within short distances. These physical properties are function of generation, mobility and degree of saturation of the leachate, gas generation, compaction density and variability. These relationships mean that it can be possible to get an overall image of the quantity and characteristics of the waste from surface electrical measurements over the landfill. In this paper, we present and discuss the results of three electrical tomographies carried out in the landfill site of Bellolampo (Palermo, Italy). The main aim of these surveys was to check the…
Spatial characterization of leachate plume using electrical resistivity tomography in a landfill composed of old and new cells (Belfort, France)
2016
International audience; Located near Belfort (France), the Etueffont landfill was in operation from 1976 to 2002 for the disposal and storage of domestic waste produced by 47,650 inhabitants. The site is comprised of the original landfill site called the old landfill (OL), in operation from 1976 to 1999, and a newer section known as the new cell (NC) which operated from 1999 to 2002. The objective of this study is to determine, using electrical resistivity tomography (ERT), the extent of the leachate plume from the OL and to monitor the efficiency of the liner of the NC. The entire Etueffont site was crisscrossed with 21 electrical profile lines which were traced in summer between 2009 and …
Collapsibility of metastable sand by non-conventional oedometer tests
2018
The stability of foundations soils could represent a clear and present threat for the conservation of even well preserved buildings, particularly for Architectural heritage conservation and land art heritage. A dramatic case is the presence of collapsible metastable sands as foundation soils, as it occurs in the sacral complex Valle dei Templi in Agrigento. This site listed by UNESCO, stands on a crest of a calcarenite cuesta, overlaying a layer of these sands. When the collapsible sand is dry, the structure is strong enough to bond the sand particles together. When the sand becomes wet, a de-structuration mechanism occurs and the soil’s strength is compromised. This paper has a twofold aim…
Impacts of wood extraction on soil: assessing rutting and soil compaction caused by skidding and forwarding by means of traditional and innovative me…
2021
AbstractIntensive forestry operations may cause soil compaction, plastic soil disturbances and rutting, which are responsible for undesirable effects on soils, vegetation and water bodies. Despite the numerous studies aimed to identify the main factors affecting soil damages, it still remains unclear whether wood extraction methods and driving direction (uphill or downhill) may affect the impacts of forest machines. This research analyses soil compaction and soil penetration resistance as well as rutting from forwarding and skidding using the same farm tractor in up- and downhill wood extraction. Rutting was estimated by 3D soil reconstruction derived by portable laser scanning (PLS) and cl…
Study of new joining technique: flat clinching
2007
In this paper a development of clinching, called flat clinching, is presented. After a press clinching process, the joined sheets have been deformed by a punch with a lower diameter against a flat die. In this way a new configuration is created with a geometry that has no discontinuity on the external surface (bottom). A new procedure has also been tested: the second step is perfomed by pressing the joint between two flat dies. This second case has revealed itself to be very effective.Tensile tests have been done to compare the joints strength among the various joining techniques. Moreover some joints have been cut to analyse the changing of the contact line shape and how its characteristic…
Simplified Procedure to Evaluate Head Losses in Drip Irrigation Laterals
2005
The lateral lines of a drip irrigation system consist of pressurized pipelines with inline or online emitters. Proper hydraulic design of drip laterals usually requires the accurate evaluation of the total head losses, represented by friction losses along the pipe and the emitters, and local losses due to the emitter connections. This paper extends the local loss evaluation procedure, previously obtained for coextruded laterals, on the basis of new experiments. In addition, a simplified procedure was proposed based on the constant outlet discharge assumption for a quick evaluation of total head losses in drip irrigation lines, taking into account the total local loss due to the emitter conn…
Experimental Analysis of Local Pressure Losses for Microirrigation Laterals
2004
The accurate design of drip irrigation laterals needs to consider the variation of hydraulic head due to pipe elevation changes, head losses along the lines, and also, at a given operating pressure, emitter discharge variations related to manufacturing variability, clogging, and water temperature. Hydraulic head variations are consequent to both the friction losses and local losses due to the in-line or on-line emitters along the pipe, which determine the contraction and subsequent enlargement of the flow streamlines. Moreover, in-line emitters usually have a smaller diameter than the pipe, and therefore an additional friction loss must be considered. Evaluation of energy losses and consequ…
A practical protocol for calibration of nutrient removal wastewater treatment models
2011
Activated sludge models can be very useful for designing and managing wastewater treatment plants (WWTPs). However, as with every model, they need to be calibrated for correct and reliable application. Activated sludge model calibration is still a crucial point that needs appropriate guidance. Indeed, although calibration protocols have been developed, the model calibration still represents the main bottleneck to modelling. This paper presents a procedure for the calibration of an activated sludge model based on a comprehensive sensitivity analysis and a novel step-wise Monte Carlo-based calibration of the subset of influential parameters. In the proposed procedure the complex calibration i…
Displacement Evolution of a Large Landslide in a Highly Fissured Clay
2019
The paper presents an analysis and modelling of the reactivation mechanism of a large landslide caused by rainfall, located in Cerda (Sicily, Italy). The study is based on data collected by means of a field investigation, carried out in order to assess the geotechnical properties of the involved material, and a three-year monitoring programme implemented to measure rain and pore water pressures as well as deep and superficial displacements. Three distinct landslides, evolving at variable rates in different directions, were recognized within the overall landslide area. The data clearly show the mechanical role of pore water pressures in the stability of the slope and point out the dependence…
Earth Bricks with Halloysite Nanoclay: Research and Experimentation for the Sustainability of Materials
2021
This paper illustrates the experimentation activities on rammed earth and nanotechnologies. The experimental research was carried out with the aim of improving the performance of rammed earth bricks with clay nanotubes, creating a ‘new material’ with reduced embodied energy and low CO2 emissions into the atmosphere. Specifically, the analysed performances are related to the compressive strength that expand their area of use as a building material.