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Foundation analysis and design
01 Jan 1968-
TL;DR: In this paper, Fondation de soutenagement et al. presented a reference record for Dimensionnement Reference Record created on 2004-09-07, modified on 2016-08-08.
Abstract: Keywords: Fondation ; Mur de soutenement ; Pieux ; Capacite portante ; Ancrage ; Dimensionnement Reference Record created on 2004-09-07, modified on 2016-08-08
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01 Jan 2016
TL;DR: In this paper, a new concrete mixture using crushed bricks as a coarse aggregate was used to study the effect of foundation stresses on the soil and the results obtained from soil exploration were adopted in the calculations of settlements and bearing capacities for foundation design.
Abstract: Cost, time and quality are the main targets in the design and implementation of any foundation. It represents an important part of any building, dam, bridge, tower, etc. The design of foundations requires: the load that will be transmitted by the structure to the foundation, knowledge of the geological conditions in order to understand the type of soil that is presented under the foundation e.g. soil nature, soil layers and groundwater depth, the behavior and stress of soil. In addition the standards of the building codes are of importance. Most problems that appear in Iraq during implementation and after finishing are related to soil and concrete problems. Especially, problems due to water or aggregate (stone and sand) or in cement manufacturing. This thesis aims to analyze soil and shallow foundations of buildings to reach the optimal type should be used to minimize cost with control over quality. Also, suggested a new sustainable material mixture for the three regions of Iraq. Mosul, Baghdad and Basrah are the regions chosen for study due to the great variation in the geology and the soil conditions. Soil investigations were done for twenty three sites in different locations of the three regions in Iraq. The geotechnical assessment included field investigations and laboratory tests. Laboratory testing was carried out to aid soil classification and to evaluate the engineering properties for the subsurface soil. The results obtained from soil exploration were adopted in the calculations of settlements and bearing capacities for foundation design. The results indicated that the soil in Mosul had high to very high plasticity. In Baghdad, the results showed that the soil had medium plasticity. Plasticity of soil in Basrah region was medium to low. The outcomes from the calculations which were based on field and laboratory tests were used to obtain the average and minimum values of the bearing capacity to be used in the proposed model. Computer models were conducted using STAAD Pro.v8i, SAP2000 & SAFE and PLAXIS softwares for design and analysis. All the models were applied for the three regions (Mosul, Baghdad and Basra) in Iraq. The building used in all softwares was (an existed building from Mosul university) of two stories (ground & 1st flower). Mat foundation was suggested for the building. A new concrete mixture using crushed bricks as a coarse aggregate was used to study the effect of foundation stresses on the soil. Results obtained from the softwares indicated that: the soil in some sites requires improvement before implementation of any building. The suitable type of foundation that should be used in the three regions of Iraq is shallow foundation type (continuous or strip and raft). Deep type foundation is suitable to be used for some parts of Basrah region. Finally, the results’ showed that using a crushed bricks as an aggregate in the concrete mixture will reduce the base pressure under the foundation as well as it is a durable material with low weight.
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Cites background or methods from "Foundation analysis and design"
...The N correction value use to define the empirical values for relative density (Dr), unit weight (γwet), angle of internal friction (ϕ) and unconfined compression strength (qu) from specified tables (Bowles, 1996)....
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...The groundwater in this area is between 50 m and 100 m deep [1, 4]....
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...The Poisson’s ratio ( ) and the modules of elasticity (Es) are the parameters used to calculate immediate settlement under shallow foundation as (Bowles, 1996): 16 Where: Se = immediate settlement for flexible foundation (m)....
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...Buildings are collapsed or destroyed mainly due to the effect of soil shear failure [1, 2]....
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...The stress under the square foundation decrease until the depth under the foundation became 5B (width of the foundation) the stress value will be zero (Bowles, 1996)....
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30 May 2019
TL;DR: In this article, the influence of the reinforcement embedded in the piles is analyzed using numerical (FEM) simulations and comparing them with tests made in the field, and a new classification of possible damages is proposed based on the analysis of the reflections observed at the end of the reinforced cage embedded in a pile partially reinforced.
Abstract: Low strain integrity tests in piles are relatively cheap, of quick execution and nondestructive. Despite all these advantages, several variables are involved and the influence of external factors can complicate the interpretation of the results. Between them, the influence of the pile reinforcement can be highlighted. In piles partially reinforced, the difference in density and elastic modulus of the concrete in different parts of the pile and the influence of the process of introducing the reinforcement bars can induce some reflections in the test that can be confused with damage in the pile and, therefore, should be taken into account to analyze the tests results. In this research, the influence of the reinforcement embedded in the piles is analyzed using numerical (FEM) simulations and comparing them with tests made in the field. A new classification of possible damages is proposed based on the analysis of the reflections observed at the end of the reinforcement cage embedded in a pile partially reinforced.
1 citations
Cites methods from "Foundation analysis and design"
...4 and specific mass of 1800 kg/m3 were adopted for all soil types covered in this research, consistent with values found in the literature [26]....
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30 Aug 2016
TL;DR: In this article, the authors demonstrate the three dimensional finite element analysis of Pahang-Selangor raw water transfer tunnel, as a reference case, where multi-stage excavation and pre-support are incorporated as intrinsic part of the model.
Abstract: Generally tunnelling in urban ground condition is not always favourable due to the tunnels’ susceptibility to major displacement especially when excavated in the soft soil and/or weak weathered rock formation. Apart from conventional support systems, pre-support measure like forepoling umbrella arch is frequently used to reinforce the ground. Modern computational tools allows the inclusion of multi-stage excavations and pre-support which was not possible in two dimensional (2D) plane strain. This paper demonstrates the three dimensional (3D) finite element analysis of Pahang-Selangor raw water transfer tunnel, as a reference case, where multi-stage excavation and pre-support are incorporated as intrinsic part of the model. The New Austrian Tunnelling Method (NATM)-3 segments which encountered Grade III weathered granite, having shallow overburden cover, was selected for numerical analysis using RS 3 software. Comparison between simulated and observed data has shown good agreement during verification
1 citations
TL;DR: In this paper, a back-analysis of soil stiffness parameters on the basis of three reported case studies is presented, where the braced wall has been considered as a continuous beam with soil from backfill side acting as load and strut as well as soil from cut side act as support.
Abstract: The construction of braced excavations in urban areas requires control of surrounding ground movements since excessive ground movements damage adjacent properties. Design of this type construction involves proper estimation of soil parameters. Prediction of these soil parameters may be done by controlled laboratory tests simulating actual field conditions. Laboratory tests carried out with small size samples sometimes do not replicate the field situations comprising variations in soil properties with depth specially for stratified soils. So, field data are largely being used for estimation of various soil parameters related to analysis and design of braced excavations. Precise prediction of parameters is possible if inverse method is used as the identified parameters are representative of macroscopic soil mass as a whole. The present paper works out back-analysis of soil stiffness parameters on the basis of three reported case studies. Here the braced wall has been considered as a continuous beam with soil from backfill side is acting as load and strut as well as soil from cut side act as support. Optimization (both constrained and unconstrained) technique is used for predicting values of coefficients of soil subgrade modulus. The predicted deflections are found to be quite close to the measured values which support the proposed method of parameter estimation.
1 citations
01 Jan 2008
TL;DR: In this article, a new type of mine backfill, known as gelfill, is investigated, which is known as Gelfill binders usually consist of alkali activators such as sodium silicate and other cementitious materials.
Abstract: Over the last three decades, mine backfilling has progressively integrated into underground mining operations. The high stresses associated with mining at depth in the Canadian Shield, also requires innovative approaches to mine backfilling to withstand the loading both during and after mining operations. Not only new or modified minefill systems are required, but a Iso new techniques are needed to increase the speed of the mining cycle for optimizing the mining operation. Three major purposes of mine backfill are known as 1) providing safe working condition, 2) maximizing ore recovery and 3) improving underground stability. Therefore, mine backfill has contributed greatly to the economies and environ mental aspects of mining industry. ln order to improve the mechanical behaviour of fi li, cementitious materials are used. These cementitious materials are expensive. As a .result the consumption of these cementitious materials has to be optimized and minimized in a way th at the required strength is met. The objective of this research is to investigate a new type of backfill, which is known as gelfill. Gelfill binders usually consist of alkali activators such as sodium silicate and the other cementitious materials. Sodium silicate has been used in waste
1 citations