scholarly journals Research on Installation Technologies of Retaining Walls with Ground Anchors

2020 ◽  
Vol 26 (1) ◽  
pp. 53-64
Author(s):  
Mindaugas Daukšys ◽  
Mindaugas Daukšys ◽  
Jūratė Mockienė
Keyword(s):  
Tensile Strength ◽  
Retaining Wall ◽  
Evaluation Criteria ◽  
Sandy Soils ◽  
Retaining Walls ◽  
Entropy Method ◽  
Mechanical Resistance ◽  
Existing Building ◽  
Groundwater Levels ◽  
Ground Anchors

With increasing level of urbanization, new buildings are erected in close proximity of existing buildings or quite close to site boundaries. Such practice affects the complexity of retaining wall installation technology. When a retaining wall is installed close to an existing building, a street or a steep slope, the stability of the wall has to be ensured first. There are cases when a retaining wall has to be strengthened by creating a permanent or temporary support, i.e. by installing ground anchors. According to literature analysis, the major problem is that a profile stops without reaching its designed depth (Van Baars). Merifield et al. distinguish three major types of anchors: circular, square and rectangular. They emphasise that anchor surface unevenness does not impact anchor resistance. According to El Nagar, most frequently anchors disintegrate due to excessive tensile strength of the anchor. The increase of this force is related to tensile strength measured in anchor testing. In this paper, three types of retaining walls with ground anchors are considered: pile wall, Berlin Wall, and sheet piling with excavation depth of 6 m. The conditions are selected as follows: when walls are installed in clay soils, sandy soils, sandy soils at high groundwater levels, and when the wall is installed next to the building. Mechanical resistance and stability of construction incline are calculated by means of GEO5 software. A survey was designed basing on the calculation results and the selected evaluation criteria. In the survey geotechnical engineers rated 18 different cases. The relevance of criteria is determined by employing the entropy method after the primary results of the survey are summarised; afterwards a multiple criteria decision analysis carried out using the utility function. The multi-criteria assessment results indicate the most rational type of a retaining wall for the chosen conditions.

scholarly journals INFLUENCE OF DISTANCE BETWEEN A RETAINING WALL AND THE EXISTING BUILDING ON STRESS-STRAIN STATE OF THE SYSTEM «RETAINING STRUCTURES – SOIL MASSIF»

2017 ◽  
Vol 2 (49) ◽  
pp. 159-170
Author(s):  
V. V. Ruchkivskyi
Keyword(s):  
Slip Surface ◽  
Mutual Influence ◽  
Retaining Wall ◽  
Retaining Walls ◽  
Deep Excavation ◽  
Existing Building ◽  
Geological Conditions ◽  
Geotechnical Problem ◽  
Solid Soil ◽  
Protective Structures

The results of work research of engineering protective structures in a densely built–up area with difficult engineering–geological conditions have been presented. The modeling of the geotechnical problem of deep excavation protection using a three-tier retaining wall has been performed.  The task of mutual influence of existing building and deep excavation with the change of distance between them is solved. The grafs of displacement’s dependence several tiers of retaining walls from the distance to an existing building have been presented. According to these data, a plot of the dependence of displacements of separate tiers of retaining walls from the distance to an existing building is constructed. The problem is solved by the finite element method using a nonlinear model of a solid soil environment. The character of the formation of zones of potential slip surface slope is revealed. The dependence of bending moments of the retaining walls from the distance to the existing building is shown. A safe location of an existing building to a deep excavation has been substinated.

Perencanaan dinding penahan tanah untuk menanggulangi kelongsoran pada kompleks peternakan ayam di Kecamatan Kandangan, Kediri, Jawa Timur

2018 ◽  
Vol 2 (2) ◽  
pp. 86
Author(s):  
Mila K. Wardani ◽  
Felicia T. Nuciferani ◽  
Mohamad F.N. Aulady
Keyword(s):  
Natural Disasters ◽  
Retaining Wall ◽  
Retaining Walls ◽  
Total Height ◽  
Safe Limit ◽  
Soil Retaining Walls

Landslide one of the natural disasters that caused many victims. Therefore, the landslide need a construction that can withstand landslide force. This study aims to plan retaining walls to prevent landslides in the farm area in Kandangan Subdistrict, Kediri Regency. The method used is to use slide analysis which is used to plan the retaining wall. In addition the planning of soil containment walls u ses several methods as a comparison. The results of this study indicate that the planning of ordinary soil retaining walls is still not enough to overcome slides. The minimum SF value that meets the safe limit of landslide prevention is 1.541 in the combination of 1/3 H terracing and the number of gabions as many as 7 with a total height of 2- 3 m .

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.

Prediction of Internal Stability for Geogrid-Reinforced Segmental Walls

2010 ◽  
Vol 163-167 ◽  
pp. 1854-1857
Author(s):  
Anuar Kasa ◽  
Zamri Chik ◽  
Taha Mohd Raihan
Keyword(s):  
Neural Networks ◽  
Artificial Neural Networks ◽  
Mathematical Models ◽  
Statistical Methods ◽  
Retaining Wall ◽  
Retaining Walls ◽  
Internal Stability ◽  
Residual Soil ◽  
Concrete Masonry ◽  
Artificial Neural

Prediction of internal stability for segmental retaining walls reinforced with geogrid and backfilled with residual soil was carried out using statistical methods and artificial neural networks (ANN). Prediction was based on data obtained from 234 segmental retaining wall designs using procedures developed by the National Concrete Masonry Association (NCMA). The study showed that prediction made using ANN was generally more accurate to the target compared with statistical methods using mathematical models of linear, pure quadratic, full quadratic and interactions.

scholarly journals Load transfer on instrumented prestressed ground anchors in sandy soil

2021 ◽  
Vol 14 (6) ◽  
Author(s):  
Alex Micael Dantas de Sousa ◽  
Yuri Daniel Jatobá Costa ◽  
Luiz Augusto da Silva Florêncio ◽  
Carina Maria Lins Costa
Keyword(s):  
Skin Friction ◽  
Sandy Soil ◽  
Load Transfer ◽  
Retaining Wall ◽  
Load Variations ◽  
Bored Pile ◽  
Ground Anchors ◽  
Anchor Testing ◽  
Wall System ◽  
Unbonded Length

abstract: This study evaluates load variations in instrumented prestressed ground anchors installed in a bored pile retaining wall system in sandy soil. Data were collected from instrumentation assembled in the bonded length of three anchors, which were monitored during pullout tests and during different construction phases of the retaining wall system. Instrumentation consisted of electrical resistance strain gauges positioned in five different sections along the bonded length. Skin friction distributions were obtained from the field load measurements. Results showed that the skin friction followed a non-uniform distribution along the anchor bonded length. The mobilized skin friction concentrated more intensely on the bonded length half closest to the unbonded length, while the other half of the bonded length developed very small skin friction. The contribution of the unbonded length skin friction to the overall anchor capacity was significant and this should be accounted for in the interpretation of routine anchor testing results. Displacements applied to the anchor head were sufficient to mobilize the ultimate skin friction on the unbonded length, but not on the bonded length. Performance of loading-unloading stages on the ground anchor intensified the transfer of load from the unbonded length to the bonded length. Long-term monitoring of the anchor after lock-off revealed that the load at the anchor bonded length followed a tendency to reduce with time and was not significantly influenced by the retaining wall construction phases.

scholarly journals Comparative in Mechanical Behavior of 6061 Aluminum Alloy Welded by Pulsed GMAW with Different Filler Metals and Heat Treatments

Materials ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4157 ◽  
Author(s):  
Isidro Guzmán ◽  
Everardo Granda ◽  
Jorge Acevedo ◽  
Antonia Martínez ◽  
Yuliana Dávila ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Tensile Strength ◽  
Aluminum Alloy ◽  
Weld Joint ◽  
Welding Process ◽  
Mechanical Resistance ◽  
6061 Aluminum Alloy ◽  
Β Phase ◽  
Welding Processes ◽  
Filler Metals

Precipitation hardening aluminum alloys are used in many industries due to their excellent mechanical properties, including good weldability. During a welding process, the tensile strength of the joint is critical to appropriately exploit the original properties of the material. The welding processes are still under study, and gas metal arc welding (GMAW) in pulsed metal-transfer configuration is one of the best choices to join these alloys. In this study, the welding of 6061 aluminum alloy by pulsed GMAW was performed under two heat treatment conditions and by using two filler metals, namely: ER 4043 (AlSi5) and ER 4553 (AlMg5Cr). A solubilization heat treatment T4 was used to dissolve the precipitates of β”- phase into the aluminum matrix from the original T6 heat treatment, leading in the formation of β-phase precipitates instead, which contributes to higher mechanical resistance. As a result, the T4 heat treatment improves the quality of the weld joint and increases the tensile strength in comparison to the T6 condition. The filler metal also plays an important role, and our results indicate that the use of ER 4043 produces stronger joints than ER 4553, but only under specific processing conditions, which include a moderate heat net flux. The latter is explained because Mg, Si and Cu are reported as precursors of the production of β”- phase due to heat input from the welding process and the redistribution of both: β” and β precipitates, causes a ductile intergranular fracture near the heat affected zone of the weld joint.

scholarly journals Numerical Modelling of Structures Adjacent to Retaining Walls Subjected to Earthquake Loading

Geosciences ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 486
Author(s):  
Xiaoyu Guan ◽  
Gopal S. P. Madabhushi
Keyword(s):  
Finite Element ◽  
Dynamic Behaviour ◽  
Retaining Wall ◽  
Free Field ◽  
Retaining Walls ◽  
Earthquake Loading ◽  
Bending Moments ◽  
Sheet Pile ◽  
Novel Approach ◽  
Active Zones

In an urban environment, it is often necessary to locate structures close to existing retaining walls due to congestion in space. When such structures are in seismically active zones, the dynamic loading attracted by the retaining wall can increase. In a novel approach taken in this paper, finite element-based numerical analyses are presented for the case of a flexible, cantilever sheet pile wall with and without a structure on the backfill side. This enables a direct comparison of the influence exerted by the structure on the dynamic behaviour of the retaining wall. In this paper, the initial static bending moments and horizontal stresses prior to application of any earthquake loading are compared to Coulomb’s theory. The dynamic behaviour of the retaining wall is compared in terms of wall-top accelerations and bending moments for different earthquake loadings. The dynamic structural rotation induced by the differential settlements of the foundations is presented. The accelerations generated in the soil body are considered in three zones, i.e., the free field, the active and the passive zones. The differences caused by the presence of the structure are highlighted. Finally, the distribution of horizontal soil pressures generated by the earthquake loading behind the wall, and in front of the wall is compared to the traditional Mononobe-Okabe type analytical solutions.

The Imperial City Terrace Locality of the Shimao City Site in Shenmu County, Shaanxi Province

2018 ◽  
Vol 18 (1) ◽  
pp. 28-37 ◽  
Keyword(s):  
Inner City ◽  
Large Scale ◽  
Retaining Wall ◽  
Complex Structure ◽  
Retaining Walls ◽  
Shaanxi Province ◽  
The Core ◽  
Construction Techniques ◽  
Starting Point ◽  
High Terrace

Abstract The Imperial City Terrace (Huangchengtai), a high terrace clad with stone retaining walls on all sides, was the core area of the Shimao Archaic City Site enclosed by the inner city and outer city. In 2016, the gate remains and the upper part of the northern section of the eastern retaining wall, which was the best preserved part of the retaining walls of the Imperial City Terrace, were excavated. The gate remains of the Imperial City Terrace consisted of the square, the outer barbican, the bastions, and the inner barbican. The square was in front of the gate, and the gateway was paved with stone slabs. The entire gate has more complex structure, more magnificent scale and more elaborate construction techniques than that of the eastern gate of the Outer City. This excavation sets a new starting point for the exploration of the large-scale stone city settlement pattern of the Longshan Age.

scholarly journals Evaluating structures derived from X-ray powder diffraction data using entropy

2014 ◽  
Vol 70 (a1) ◽  
pp. C104-C104
Author(s):  
Dubravka Sisak Jung ◽  
Lynne McCusker ◽  
Christian Baerlocher ◽  
Christopher Gilmore
Keyword(s):  
Powder Diffraction ◽  
Evaluation Criteria ◽  
Entropy Method ◽  
Basis Set ◽  
Solution Quality ◽  
Powder Charge ◽  
X Ray ◽  
Density Maps ◽  
Straightforward Method ◽  
All Solutions

So far, in the field of X-ray powder diffraction, the maximum entropy method (MEM) has been used to (i) solve the phase problem, (ii) estimate the intensities of overlapping reflections, (iii) predict the intensities of missing reflections, and (iv) improve electron density maps generated during Rietveld refinement. We found a new application for MEM in a recent study, in which the powder charge flipping algorithm [1] in Superflip was applied to all-light-atom structures [2]. It proved to be difficult to identify the few fully interpretable maps within in the 200 generated in a typical Superflip job using the standard evaluation criteria. In 1992, Sato reported that entropy could be used as a solution evaluation criterion if the basis set is large, the phases are close to the correct ones, and the structure contains a small molecule [3]. Reasoning that these requirements would be fulfilled by the better Superflip solutions, all solutions were input to the MEM program MICE to calculate the corresponding ME maps and their entropies. Tests performed on several datasets showed no direct correlation between entropy and the solution quality. However, it was noted that a certain number of solutions show entropy values significantly lower than the others. This group usually contained one fully interpretable map. Refinement of the approach led to a relatively straightforward method for recognizing the better solutions. Furthermore, phase recycling based on this approach proved to be useful. As a result, guidelines for solving structures of different levels of complexity using the pCF algorithm could be devised.

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