Stabilization of Embankment Slope with Geofoam

Author(s):  
Walter S. Jutkofsky ◽  
J. Teh Sung ◽  
Dawit Negussey

A case history is presented describing the use of expanded polystyrene (EPS) geofoam blocks to treat an unstable roadway embankment slope involving clayey soils. The selection of the geofoam treatment was based upon its ability to be constructed and have the least impact on both the environment and adjacent homeowners. The site subsurface conditions, engineering properties of EPS, design analysis, and construction phases are reviewed. Potential traffic safety problems associated with differential icing of roadways caused by the presence of geofoam blocks beneath the pavements were minimized by using a thicker subbase layer in the geofoam-treated area. Data from an instrumentation program consisting of an inclinometer, extensometers, and thermistors are presented. Pavement temperature readings collected from areas with and without geofoam treatment are compared to investigate potential differential icing on the roadway.

Sensors ◽  
2012 ◽  
Vol 12 (11) ◽  
pp. 14711-14729 ◽  
Author(s):  
Enrique Cabello ◽  
Cristina Conde ◽  
Isaac Diego ◽  
Javier Moguerza ◽  
Andrés Redchuk
Keyword(s):  

Author(s):  
Khelifa Harichane ◽  
Mohamed Ghrici ◽  
Said Kenai

Cohesive soils with a high plasticity index present difficulties in construction operations because they usually contain expansive clay minerals. However, the engineering properties of soils can be improved by different techniques. The aim of this paper is to study the effect of using lime, natural pozzolana or a combination of both lime and natural pozzolana on plasticity, compaction and shear strength of two clayey soils classified as CH and CL according to the unified soil classification system (USCS). The obtained results indicated that for CH class clay soil, the plasticity index decreased significantly for samples stabilized with lime. On the other hand, for the soil classified as CL class clay, a high decrease in the plasticity index value was observed for samples stabilized with natural pozzolana compared to those stabilized with lime. Also, both the cohesion and internal friction angle in lime added samples were demonstrated to increase with time. The combination of lime and natural pozzolana exhibits a significant effect on the enhancement of both the cohesion and  internal friction angle at later stages. The lime-natural pozzolana combination appears to produce higher shear strength parameters than lime or natural pozzolana used alone.


Author(s):  
Mohamed-Asem U. Abdul-Malak ◽  
David W. Fowler ◽  
Cesar A. Constantino

A study was undertaken to identify the engineering properties of aggregates that explain the variability in the frictional performance of seal coat highway overlays. The frictional performance data of 72 test sections and section replicates collected over a period of 8 years were used in the formulation of statistical models that incorporate the significant variables. The effects of traffic, construction, and environmental variables were also considered. Formulated models were of two types: general and individual. The former type attempts to describe frictional performance using the observations collected on all aggregate materials used. The latter describes the performance of individual aggregate groups. Laboratory properties found to be significant included the polish value, impact and abrasion, and soundness properties. The coating of aggregate particles, gradation, and construction placing rates of aggregate and asphalt were also shown to be significant in explaining performance variability. The influence of traffic and region was found to be interactive with the type and properties of aggregates. The formulated models can be used as a tool for predicting the frictional performance of seal coat aggregates, thus providing a better means for the proper selection of aggregates and for the planning of future seal coat construction projects.


Author(s):  
Adeniran Jolaade ADEALA ◽  
Olugbenga Babajide SOYEM

Expanded polystyrene (EPS) wastes are generated from industries and post-consumer products. They are non-biodegradable but are usually disposed by burning or landfilling leading to environmental pollution. The possibility of using EPS as partial replacement for fine aggregates in concrete has generated research interests in recent times. However, since the physical and mechanical properties of EPS are not like those of conventional fine aggregates, this study is focussed on the use of EPS as an additive in concrete while keeping other composition (sand and granite) constant. Expanded polystyrene was milled, the bulk density of EPS was 10.57kg/m3 and particle size distributions were determined. Engineering properties of expanded polystyrene concrete were determined in accordance with BS 8110-2:1985. The result showed that the amount of expanded polystyrene incorporated in concrete influence the properties of hardened and fresh concrete. The compressive strengths of 17.07MPa with 5 % expanded polystyrene concrete at 28 days for example can be used as a lightweight concrete for partitioning in offices. Incorporating expanded polystyrene granules in a concrete matrix can produce lightweight polystyrene aggregate concrete of various densities, compressive strengths, flexural strengths and tensile strengths. In conclusion, this reduces environmental pollution, reduction in valuable landfill space and also for sustainability in construction companies


Buildings ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 238 ◽  
Author(s):  
Stamoulis ◽  
Santos ◽  
Lenz ◽  
Tusset

The rational use of energy has motivated research on improving the energy efficiency of buildings, which are responsible for a large share of world consumption. A strategy to achieve this goal is the application of optimized thermal insulation on a building envelope to avoid thermal exchanges with the external environment, reducing the use of heating, ventilation and air-conditioning (HVAC) systems. In order to contribute to the best choice of insulation applied to an industrial shed roof, this study aims to provide an optimization tool to assist this process. Beyond the thermal comfort and cost of the insulation, some hygrothermic properties also have been analysed to obtain the best insulation option. To implement this optimization technique, several thermo-energetic simulations of an industrial shed were performed using the Domus software, applying 4 types of insulation material (polyurethane, expanded polystyrene, rockwool and glass wool) on the roof. Ten thicknesses ranging from 0.5 cm to 5 cm were considered, with the purpose of obtaining different thermal comfort indexes (PPD, predicted percentage dissatisfied). Posteriorly, the best insulation ranking has been obtained from the weights assigned to the parameters in the objective function, using the technique of the genetic algorithm (GA) applied to multi-criteria selection. The optimization results showed that polyurethane (PU) insulation, applied with a thickness of 1 cm was the best option for the roof, considering the building functional parameters, occupant metabolic activity, clothing insulation and climate conditions. On the other hand, when the Brazilian standard was utilized, rock wool (2 cm) was considered the best choice.


Energies ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 4202
Author(s):  
Qihong Feng ◽  
Jiawei Ren ◽  
Xianmin Zhang ◽  
Xianjun Wang ◽  
Sen Wang ◽  
...  

Refracturing technology is one of the key technologies to recover the productivity of horizontal wells in tight oil reservoirs, and the selection of best candidate wells from target blocks is the basis of this technology. Based on the refracturing production database, this paper analyzes the direct relationship between geological data, initial fracturing completion data, and dynamic production data, and the stimulation effect of refracturing. Considering the interaction among multiple factors, the factors affecting the stimulation effect of refracturing are classified and integrated, and a comprehensive index including geology, engineering, and production is constructed, making this index meaningful both for physical and engineering properties. The XGBoost decision tree model is established to analyze the weight of influence for the comprehensive index of geology, engineering, and production in predicting the stimulation effect of refracturing. A comprehensive decision index of refracturing well selection is formed by combining the above three for performing a fast selection of horizontal candidate wells for fracturing. Taking a horizontal well test area in Songliao Basin as an example, the target wells of refracturing are selected by this method, and field operation is carried out, and a good stimulation effect is achieved. The results show that the comprehensive decision-making index constructed by this method is reliable and has certain guiding significance for well selection and stimulation potential evaluation of tight oil reservoir.


2003 ◽  
Vol 37 (5-6) ◽  
pp. 631-640 ◽  
Author(s):  
A Burghignoli ◽  
M Cocciuti ◽  
S Miliziano ◽  
F.M Soccodato

2010 ◽  
Vol 56 (3) ◽  
pp. 247-256 ◽  
Author(s):  
Jerzy Kolakowski ◽  
Jacek Cichocki ◽  
Piotr Makal ◽  
Ryszard Michnowski

An Ultra-Wideband System for Vehicle PositioningSystems supporting traffic safety require precise information on a vehicle position. The paper contains a proposal for a vehicle localization system based on ultra-wideband (UWB) technology. The system allows for vehicle positioning with submeter accuracy. The paper presents a system concept and an algorithm used for position calculation. The algorithm consists in selection of a system configuration in order to decrease the positioning uncertainty. The system concept was verified with a developed system demonstrator. The paper contains a description of the devices comprising the system. Exemplary results of outdoor demonstrator tests are included and discussed. The tests confirmed efficiency and attractiveness of the proposed solution.


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