scholarly journals Construction Cost Analysis of Retaining Walls

2020 ◽  
Vol 9 (4) ◽  
pp. 1909-1914
Keyword(s):  
Urban Areas ◽  
Ground Surface ◽  
Retaining Walls ◽  
Soil Mass ◽  
Strength Properties ◽  
Wall Material ◽  
Sharp Change ◽  
Finite Element Software ◽  
Special Cases ◽  
The Cost

Retaining walls are relatively rigid walls used to support the ground laterally so that it can be held at different levels on both sides [1]. Retaining walls are considered all technical works, which allow the implementation of a sharp change in the level of the earth's surface, in such a way that the ground-construction system presents limited displacement or is marginally restrained. Support structures are mainly used in cases of disruption of soil continuity resulting from an excavation, below the natural surface of the ground, such as when building roads in a difficult geographical terrain with steep slopes. It is also common for them to be used in the construction of basements in urban areas, when there are other buildings or roads around the perimeter. In special cases, functional reasons impose the local elevation of the ground surface with grounding in the area around the construction, such as on bridge piers or in port projects, so it becomes necessary to support the soil mass. Finally, the construction of retaining walls becomes necessary to stabilize and protect natural slopes that present kinematic instability. The purpose of the present work is to compare the cost of constructing three retaining walls (gravity, cantilever, braced) subject to identical ground pressures. The retaining walls were designed using the same finite element software (GEO5), taking into account common parameters for the soil stress, the strength properties of the soil mass, the wall material as well as the diameter of the reinforcing steel bars, so that the results can be absolutely comparable. The market research that followed produced interesting conclusions on the comparison of the cost estimates for the three retaining walls

scholarly journals 3D MODELLING OF TUNNEL EXCAVATION USING PRESSURIZED TUNNEL BORING MACHINE IN OVERCONSOLIDATED SOILS

2013 ◽  
Vol 35 (2) ◽  
pp. 3-17 ◽  
Author(s):  
Rafik Demagh ◽  
Fabrice Emeriault
Keyword(s):  
Numerical Simulation ◽  
Urban Areas ◽  
Three Dimensional ◽  
Ground Surface ◽  
Tunnel Boring Machine ◽  
Confining Pressure ◽  
Soil Mass ◽  
Shield Tunnel ◽  
Tunnel Boring ◽  
Boring Machines

Abstract The construction of shallow tunnels in urban areas requires a prior assessment of their effects on the existing structures. In the case of shield tunnel boring machines (TBM), the various construction stages carried out constitute a highly three-dimensional problem of soil/structure interaction and are not easy to represent in a complete numerical simulation. Consequently, the tunnelling- induced soil movements are quite difficult to evaluate. A 3D simulation procedure, using a finite differences code, namely FLAC3D, taking into account, in an explicit manner, the main sources of movements in the soil mass is proposed in this paper. It is illustrated by the particular case of Toulouse Subway Line B for which experimental data are available and where the soil is saturated and highly overconsolidated. A comparison made between the numerical simulation results and the insitu measurements shows that the 3D procedure of simulation proposed is relevant, in particular regarding the adopted representation of the different operations performed by the tunnel boring machine (excavation, confining pressure, shield advancement, installation of the tunnel lining, grouting of the annular void, etc). Furthermore, a parametric study enabled a better understanding of the singular behaviour origin observed on the ground surface and within the solid soil mass, till now not mentioned in the literature.

scholarly journals The model of energy efficiency transportation of thermal and electric energy in the underground heat collector

2019 ◽  
Vol 100 ◽  
pp. 00081
Author(s):  
Dmitriy Titkov
Keyword(s):  
Urban Areas ◽  
Electric Energy ◽  
Thermal Conditions ◽  
Soil Mass ◽  
Significant Cost ◽  
Temperature Variations ◽  
Cost Cutting ◽  
Air Space ◽  
Heat Collector ◽  
The Cost

The paper deals with modeling of the underground heat collector thermal conditions for utilities, calculating variations in temperature taking place in the soil mass around the collector as well as temperature variations in the air space of the latter. This leads to the reduction in the cost of heat and electricity transportation and a significant cost cutting of heat that is electricity supply of urban areas. The dependences of the thermal soil massiveness on the laying depth of the collector and changes in soil temperature in the course of time are presented.

scholarly journals Black Hole Algorithm for Sustainable Design of Counterfort Retaining Walls

2020 ◽  
Vol 12 (7) ◽  
pp. 2767 ◽  
Author(s):  
Víctor Yepes ◽  
José V. Martí ◽  
José García
Keyword(s):  
Black Hole ◽  
Sustainable Design ◽  
Retaining Walls ◽  
The Other ◽  
Trade Off ◽  
Construction Company ◽  
Geometric Variables ◽  
The Stability ◽  
The Cost ◽  
Black Hole Algorithm

The optimization of the cost and CO 2 emissions in earth-retaining walls is of relevance, since these structures are often used in civil engineering. The optimization of costs is essential for the competitiveness of the construction company, and the optimization of emissions is relevant in the environmental impact of construction. To address the optimization, black hole metaheuristics were used, along with a discretization mechanism based on min–max normalization. The stability of the algorithm was evaluated with respect to the solutions obtained; the steel and concrete values obtained in both optimizations were analyzed. Additionally, the geometric variables of the structure were compared. Finally, the results obtained were compared with another algorithm that solved the problem. The results show that there is a trade-off between the use of steel and concrete. The solutions that minimize CO 2 emissions prefer the use of concrete instead of those that optimize the cost. On the other hand, when comparing the geometric variables, it is seen that most remain similar in both optimizations except for the distance between buttresses. When comparing with another algorithm, the results show a good performance in optimization using the black hole algorithm.

scholarly journals Cost of Management of Diabetes Mellitus: A Pan India Study

2021 ◽  
pp. 097275312199849
Author(s):  
Raghuram Nagarathna ◽  
M Madhava ◽  
Suchitra S Patil ◽  
Amit Singh ◽  
K. Perumal ◽  
...  
Keyword(s):  
Diabetes Mellitus ◽  
Urban Areas ◽  
Noncommunicable Disease ◽  
Cost Of Treatment ◽  
Rural And Urban Areas ◽  
Cost Of Disease ◽  
Rural And Urban ◽  
Significant Difference ◽  
The Cost ◽  
Prevalence Of Diabetes Mellitus

Background: Diabetes mellitus is a major noncommunicable disease. While mortality rates are increasing, the costs of managing the disease are also increasing. The all-India average monthly expenditure per person (pppm) is reported to be ₹ 1,098.25, which translates to an annual expenditure of ₹13,179 per person. Purpose: While a number of studies have gone into the aspect of the cost of disease management, we do not find any study which has pan-India reach. We also do not find studies that focus on differences (if any) between rural and urban areas, age or on the basis of gender. We planned to report the cost of illness (COI) in diabetes individuals as compared to others from the data of a pan-India trial. Methods: Government of India commissioned the Indian Yoga Association to study the prevalence of diabetes mellitus in India in 2017. As part of the questionnaire, the cost of treatment was also captured. Data collected from 25 states and union territories were analyzed using the analysis of covriance (ANCOVA) test on SPSS version 21. Results: There was a significant difference ( P < .05) between the average expenses per person per month (pppm) of individuals with self-reported known diabetes (₹1,357.65 pppm) and others (unknown and/or nondiabetes individuals–₹ 999.91 pppm). Similarly, there was a significant difference between rural (₹2,893 pppm) and urban (₹4,162 pppm) participants and between those below (₹1,996 pppm) and above 40 years (₹5,059 pppm) of age. Conclusion: This preliminary report has shown that the COI because of diabetes is significantly higher than others pointing to an urgent need to promote disease-preventive measures.

scholarly journals Cost of groundwater protection: major groundwater basin protection zones in Poland

2021 ◽  
Author(s):  
Ewa Krogulec ◽  
Jacek Gurwin ◽  
Mirosław Wąsik
Keyword(s):  
Urban Areas ◽  
Groundwater Protection ◽  
Social Economy ◽  
Land Development ◽  
Cost Benefit ◽  
Legal Framework ◽  
Legal Analysis ◽  
Protection Zones ◽  
Groundwater Basins ◽  
The Cost

AbstractThis paper describes the complex hydrogeological, legal framework and socioeconomic costs of the groundwater protection in major groundwater basins (MGBs) in Poland in accordance with European directives. The hydrogeological criteria developed in Poland for establishing MGBs and the principles of their protection provide more details to the directives that are in force in Europe, which define the general principles for groundwater protection. The procedure of establishing MGB protection zones is connected with a change in local plans and land development and requires an analysis of the cost–benefit relationship in the sphere of social economy in the sector of public economics. The cost assessment was performed on the basis of data from hydrogeological documentations, and the aggregation of subareas to which the same existing and planned development can be attributed. A legal analysis of bans, orders and restrictions together with the identification of the risk of claims in specific hydrogeological and development conditions was a fundamental issue of research. These costs depend on the acreage and land use of the protected area. The unit costs of MGB protection, calculated per 1 km2 of the protection area, for six sample basins were estimated at €120 to €208,000/2 years/1 km2. The highest costs are generated by establishing protection in urban areas, while the lowest costs are generated in forest areas.

scholarly journals Structural Behavior of Prefabricated Ecological Grid Retaining Walls and Application in a Highway in China

Symmetry ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 746
Author(s):  
Xinquan Wang ◽  
Cong Zhu ◽  
Hongguo Diao ◽  
Yingjie Ning
Keyword(s):  
Retaining Wall ◽  
Contact Point ◽  
Retaining Walls ◽  
Wall Structure ◽  
Soil Arching ◽  
Finite Element Software ◽  
Study Results ◽  
Stress And Deformation ◽  
Asymmetrical Condition ◽  
Construction Efficiency

The retaining wall is a common slope protection structure. To tackle the current lack of sustainable and highly prefabricated retaining walls, an environmentally friendly prefabricated ecological grid retaining wall with high construction efficiency has been developed. Due to the asymmetrical condition of the project considered in this paper, the designed prefabricated ecological grid retaining wall was divided into the excavation section and the filling section. By utilizing the ABAQUS finite element software, the stress and deformation characteristics of the retaining wall columns, soil, anchor rods, and inclined shelves in an excavation section, and the force and deformation relationships of the columns, rivets, and inclined shelves in three working conditions in a filling section were studied. The study results imply that the anchor rods may affect the columns in the excavation section and the stress at the column back changes in an M-shape with height. Moreover, the peak appears at the contact point between the column and the anchor rod. The displacement of the column increases slowly along with the height, and the column rotates at its bottom. In the excavation section, the stress of the anchor rod undergoes a change at the junction of the structure. The inclined shelf is an open structure and is very different from the retaining plate structure of traditional pile-slab retaining walls. Its stress distribution follows a repeated U-shaped curve, which is inconsistent with the trend of the traditional soil arching effect between piles, which increases first and then decreases. For the retaining wall structure in the filling section, the numerical simulated vehicle load gives essentially consistent results with the effects of the equivalent filling on the concrete column.

scholarly journals The Interaction Features of the Multi-Level Retaining Walls with Soil Mass

2017 ◽  
Vol 26 (3) ◽  
pp. 179-190
Author(s):  
Igor Boyko ◽  
Liudmyla Skochko ◽  
Veronica Zhuk
Keyword(s):  
Numerical Modelling ◽  
Numerical Simulations ◽  
Variable Stiffness ◽  
Retaining Walls ◽  
Soil Mass ◽  
Soil Base ◽  
Deep Foundation ◽  
Multi Level ◽  
Horizontal Displacements

Abstract The interaction features of multi-level retaining walls with soil base were researched by changing their geometric parameters and locality at the plan. During excavation of deep foundation pits it is important to choose the type of constructions which influences on the horizontal displacements. The distance between the levels of retaining walls should be based on the results of numerical modelling. The objective of this paper is to present a comparison between the data of numerical simulations and the results of the in-situ lateral tests of couple piles. The problems have been solved by using the following soil models: Coulomb-Mohr model; model, which is based on the dilatation theory; elastic-plastic model with variable stiffness parameters.

A Digital Terrain Modeling Method in Urban Areas by the ICESat-2 (Generating precise terrain surface profiles from photon-counting technology)

2021 ◽  
Vol 87 (4) ◽  
pp. 237-248
Author(s):  
Nahed Osama ◽  
Bisheng Yang ◽  
Yue Ma ◽  
Mohamed Freeshah
Keyword(s):  
Urban Areas ◽  
Spatial Clustering ◽  
Photon Counting ◽  
Ground Surface ◽  
Ground Truth ◽  
Surface Model ◽  
Laser Altimeter ◽  
Ground Truth Data ◽  
Urban Scenes ◽  
Terrain Surface

The ICE, Cloud and land Elevation Satellite-2 (ICES at-2) can provide new measurements of the Earth's elevations through photon-counting technology. Most research has focused on extracting the ground and the canopy photons in vegetated areas. Yet the extraction of the ground photons from urban areas, where the vegetation is mixed with artificial constructions, has not been fully investigated. This article proposes a new method to estimate the ground surface elevations in urban areas. The ICES at-2 signal photons were detected by the improved Density-Based Spatial Clustering of Applications with Noise algorithm and the Advanced Topographic Laser Altimeter System algorithm. The Advanced Land Observing Satellite-1 PALSAR –derived digital surface model has been utilized to separate the terrain surface from the ICES at-2 data. A set of ground-truth data was used to evaluate the accuracy of these two methods, and the achieved accuracy was up to 2.7 cm, which makes our method effective and accurate in determining the ground elevation in urban scenes.

Links between pond and dike, their potential and impacts on livelihood.

2020 ◽  
Author(s):  
Manjurul Karim ◽  
Md. Abdul Wahab ◽  
David Little ◽  
Md. Shamsul ◽  
V. Marc
Keyword(s):  
Urban Areas ◽  
Water Reservoir ◽  
Fish Farming ◽  
Important Food ◽  
Urban Households ◽  
Productive System ◽  
Principal Source ◽  
The Cost ◽  
Inland Water Bodies

Abstract Aquaculture and horticulture are interlinked and both of these agricultural components have considerable importance in the economy of Bangladesh. Most people in this country depend on fish as the principal source of animal protein. Vegetables are also considered by Bangladeshi people as important food items and as a source of micronutrients. Ponds, among various inland water bodies, are the most important water reservoir, providing access to fish, irrigation for surrounding vegetables and rice crops and water for family use, and thus are an integral part of rural and peri-urban households. Integration of crops with fish farming through pond-dike systems may be an economically viable and productive system for both richer and poorer farmers in rural and peri-urban areas in Bangladesh. High-cost inputs in fish farming are not needed in such pond-dike systems, therefore reducing the cost of inputs, provided that there is proper integration between pond and crops grown in the vicinity. A community-level assessment of the importance and role of pond-dike systems and a baseline study, carried out in villages in Mymensingh district in early 2002 by the Pondlive project funded by the European Commission, are outlined.

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