scholarly journals Multi-Criteria Parametric Verifications for Stability Diagnosis of Rammed-Earth Historic Urban Ramparts Working as Retaining Walls

2021 ◽  
Vol 11 (6) ◽  
pp. 2744
Author(s):  
Álvaro R. Serrano-Chacón ◽  
Emilio J. Mascort-Albea ◽  
Jacinto Canivell ◽  
Rocío Romero-Hernández ◽  
Antonio Jaramillo-Morilla
Keyword(s):  
Retaining Wall ◽  
Earth Pressure ◽  
Retaining Walls ◽  
International Committee ◽  
Lateral Earth Pressure ◽  
Research Sector ◽  
Overall Stability ◽  
Urban Contexts ◽  
And Control

Institutions such as ICOFORT (International committee on fortifications and military heritage) encourages the development of diagnosis strategies for the conservation and maintenance of historic earthen walls as highly necessary. Thus, it is important to be aware of the conditions in urban contexts, where the deterioration can be more aggressive and the risk of damage increases. Despite this, there are many strategies of constructive diagnosis for these kinds of monuments, but not many of them are concerned with the structural assessment of situations in which the ramparts work as a retaining wall in an unforeseen way. The medieval ramparts of Seville (Spain) are shown as a completely representative case study of the above-mentioned situation. In the research sector, the monument resists the lateral earth pressure developed by the new difference in height at both sides of the wall. Based on the limited states principle and on different international codes formulation, a tool was programmed to carry out automatic calculations to verify the case study’s overall stability conditions using standard sections. The obtained results were based on the overturning, bearing, and sliding overdesign factors (ODF) and determined a stable situation that could be at risk because of changes in the surrounding such as, excavations or the movements of the ground water table, or seismic events. Thus, the need and usefulness of strategies and control instruments that should be integrated into heritage intervention projects have been proved.

scholarly journals Evaluating the Role of Geofoam Properties in Reducing Lateral Loads on Retaining Walls: A Numerical Study

2021 ◽  
Vol 13 (9) ◽  
pp. 4754
Author(s):  
Muhammad Imran Khan ◽  
Mohamed A. Meguid
Keyword(s):  
Numerical Study ◽  
Retaining Wall ◽  
Earth Pressure ◽  
Retaining Walls ◽  
Expanded Polystyrene ◽  
Wall Structure ◽  
Eps Geofoam ◽  
Lateral Earth Pressure ◽  
Backfill Soil

Expanded polystyrene (EPS) geofoam is a lightweight compressible material that has been widely used in various civil engineering projects. One interesting application of EPS in geotechnical engineering is to reduce the lateral earth pressure on rigid non-yielding retaining walls. The compressible nature of the EPS geofoam allows for the shear strength of the backfill soil to be mobilized, which leads to a reduction in lateral earth pressure acting on the wall. In this study, a finite element model is developed and used to investigate the role of geofoam inclusion between a rigid retaining wall and the backfill material on the earth pressure transferred to the wall structure. The developed model was first calibrated using experimental data. Then, a parametric study was conducted to investigate the effect of EPS geofoam density, relative thickness with respect to the wall height, and the frictional angle of backfill soil on the effectiveness of this technique in reducing lateral earth pressure. Results showed that low-density EPS geofoam inclusion provides the best performance, particularly when coupled with backfill of low friction angle. The proposed modeling approach has shown to be efficient in solving this class of problems and can be used to model similar soil-geofoam-structure interaction problems.

Performance of Back-to-Back Geogrid Reinforced Soil Retaining Walls for Railways during Service

2021 ◽  
pp. 036119812110242
Author(s):  
Guangqing Yang ◽  
Yunfei Zhao ◽  
Zhijie Wang ◽  
He Wang
Keyword(s):  
Retaining Wall ◽  
Good Condition ◽  
Earth Pressure ◽  
Retaining Walls ◽  
Reinforced Soil ◽  
Vertical Stress ◽  
Peak Strain ◽  
Lateral Earth Pressure ◽  
Reinforced Retaining Wall ◽  
Soil Retaining Walls

To investigate the performance of a reinforced soil retaining wall during service for a passenger-dedicated railway, long-term remote observation testing of the back-to-back geogrid reinforced retaining wall (BBGRSW) of Qing-Rong passenger-dedicated railway in Shandong Province was conducted for 60 months. The performance of the reinforced retaining wall was investigated after construction, and the lateral earth pressure of the reinforced soil wall was analyzed. The vertical stress on the wall and tension on the geogrid were measured using pressure cells and flexible deformation gauges, thereby resulting in the distribution of data and changes in the service period. The test results show that the pressure and deformation of the wall are almost stable. It was determined that the lateral earth pressure on the back of the wall panel was approximately 119.2% of the completion time during the 60 months after construction. The vertical stress on the reinforced soil retaining wall remained approximately stable 60 months post-construction. The maximum strain of the measured geogrids accounted for less than 30% of the peak strain. Moreover, the deformation of the wall was relatively small, which indicated that both sides of the wall remained in good condition. These research results can serve as a reference for the design optimization of reinforced soil retaining walls for high-speed railways.

Lateral Earth Pressure Coefficient of Soils Subjected to Freeze–Thaw

2017 ◽  
Vol 140 (2) ◽  
Author(s):  
Xiaodong Zhao ◽  
Guoqing Zhou ◽  
Bo Wang ◽  
Wei Jiao ◽  
Jing Yu
Keyword(s):  
Pressure Coefficient ◽  
Earth Pressure ◽  
Retaining Walls ◽  
Saturated Soil ◽  
Frozen Soils ◽  
Freeze Thaw ◽  
Lateral Earth Pressure ◽  
Soil Deposits ◽  
Earth Pressure Coefficient ◽  
Water Saturated

Artificial frozen soils (AFS) have been used widely as temporary retaining walls in strata with soft and water-saturated soil deposits. After excavations, frozen soils thaw, and the lateral earth pressure penetrates through the soils subjected to freeze–thaw, and acts on man-made facilities. Therefore, it is important to investigate the lateral pressure (coefficient) responses of soils subjected to freeze–thaw to perform structure calculations and stability assessments of man-made facilities. A cubical testing apparatus was developed, and tests were performed on susceptible soils under conditions of freezing to a stable thermal gradient and then thawing with a uniform temperature (Fnonuni–Tuni). The experimental results indicated a lack of notable anisotropy for the maximum lateral preconsolidated pressures induced by the specimen’s compaction and freeze–thaw. However, the freeze–thaw led to a decrement of lateral earth pressure coefficient  K0, and  K0 decrement under the horizontal Fnonuni–Tuni was greater than that under the vertical Fnonuni–Tuni. The measured  K0 for normally consolidated and over-consolidated soil specimens exhibited anisotropic characteristics under the vertical Fnonuni–Tuni and horizontal Fnonuni–Tuni treatments. The anisotropies of  K0 under the horizontal Fnonuni–Tuni were greater than that under the vertical Fnonuni–Tuni, and the anisotropies were more noticeable in the unloading path than that in the loading path. These observations have potential significances to the economical and practical design of permanent retaining walls in soft and water-saturated soil deposits.

Research on Calculation Formula of Retaining Wall for Structural Reliability Program Design

2013 ◽  
Vol 275-277 ◽  
pp. 1154-1157
Author(s):  
Yun Lian Song ◽  
Si Li ◽  
Jian Ran Cao
Keyword(s):  
Safety Factor ◽  
Structural Reliability ◽  
Program Design ◽  
Retaining Wall ◽  
Earth Pressure ◽  
Retaining Walls ◽  
Wall Structure ◽  
Active Earth Pressure ◽  
Material Parameters ◽  
Simplified Formula

Stability problem of gravity retaining wall structure was researched, and a simplified formula of the active earth pressure Ea was turned out for the convenience of the program design. The anti-slide safety factor K0 and anti-overturning safety factor Kc were derived based on different positions of slip plane of retaining wall. This work is the basis of the reliability calculating and program design, for these formulas must be used in anti-slide and anti-overturning safety failure mode in program compiling. On the basis of the known parameters such as wall type, wall dimensions, material parameters, external load, and so on, the program can automatically calculate K0 and Kc, their corresponding failure probability Pf and reliability index β can easily be calculated in later analysis. The research content provide a convenient calculation method, which is used to calculate the Ea and K0 and Kc and Pf and β of the actual retaining walls engineering.

Numerical Simulation on the Stress Characteristics of Prestressed Retaining Wall

2013 ◽  
Vol 477-478 ◽  
pp. 596-599
Author(s):  
Jian Qing Wu ◽  
Hong Bo Zhang ◽  
Xiu Guang Song ◽  
Yi Fan Yu ◽  
Chao Li
Keyword(s):  
Numerical Simulation ◽  
Stress Distribution ◽  
Bearing Capacity ◽  
Retaining Wall ◽  
Earth Pressure ◽  
Lateral Earth Pressure ◽  
Prestressed Anchor

With the highway subgrade fill increasing, traditional retaining wall cannot meet the requirements for supporting. To meet this requirement, the prestressed opposite-pull retaining wall was put forward. Due to the anchor pull of the new-style retaining wall, its bearing capacity was enhanced, but the stress is not clear. In order to reveal the stress distribution of the prestressed opposite-pull retaining wall, FLAC3D was adept to do numerical simulation on the new-style retaining wall. It simulated three conditions of the wall with no anchor, with anchor but without prestress and with prestressed anchor. The results showed that, after the layout of prestressed anchor, the lateral earth pressure of the region near the anchor increased with the increase of prestress, the lateral earth pressure of the wall is parabola distribution. The lateral earth pressure was larger than that of the wall with no anchor and with anchor but without prestress. The bearing capacity of the retaining wall was effectively improved.

scholarly journals The stability of the Corrugated Concrete Sheet Pile (CCSP) of the Soil Retaining Wall at the Abutmen Bridge Bh 1751 in Lok Ulo District, Kebumen

2018 ◽  
Vol 3 (1) ◽  
Author(s):  
Septiana Widi Astuti ◽  
Ayu Prativi
Keyword(s):  
Rolling Force ◽  
Retaining Wall ◽  
Earth Pressure ◽  
Deep Excavation ◽  
Safety Requirements ◽  
Lateral Earth Pressure ◽  
Bridge Abutment ◽  
Excavation Work ◽  
The Stability ◽  
Flexible Retaining Wall

Abutment bridge is a building under the bridge located on both sides of the bridge end. The process of building a bridge abutment often requires excavation to the depth of the abutment base so that the abutment reinforcement and casting work can be carried out. In deep excavation work, each side of the excavation needs to be installed in a flexible retaining wall type (plaster) first. In this study, CCSP stability analysis was carried out on earth excavation work for abutment bridge BH 1751. The calculation method starts from determining the lateral earth pressure acting on the soil, then determining the depth of CCSP planting that is able to produce CCSP stability on the rolling force. The analysis shows that the depth of CCSP planting that meets the safety requirements of the rolling force is 20 m

scholarly journals Effect of Wall Inclination on Dynamic Active Thrust for Cohesive Soil Backfill

2018 ◽  
Vol 9 (2) ◽  
pp. 6 ◽  
Author(s):  
A. Gupta ◽  
V. Yadav ◽  
V. A. Sawant ◽  
R. Agarwal
Keyword(s):  
Retaining Wall ◽  
Earth Pressure ◽  
Cohesive Soil ◽  
Retaining Walls ◽  
Wall Friction ◽  
Cohesionless Soil ◽  
Active Earth Pressure ◽  
Seismic Active Earth Pressure ◽  
Design Charts ◽  
Seismic Loadings

Design of retaining walls under seismic conditions is based on the calculation of seismic earth pressurebehind the wall. To calculate the seismic active earth pressure behind the vertical retaining wall, many researchers reportanalytical solutions using the pseudo-static approach for both cohesionless and cohesive soil backfill. Design charts havebeen presented for the calculation of seismic active earth pressure behind vertical retaining walls in the non-dimensionalform. For inclined retaining walls, the analytical solutions for the calculation of seismic active earth pressure as well as thedesign charts (in non-dimensional form) have been reported in few studies for c-ϕ soil backfill. One analytical solution forthe calculation of seismic active earth pressure behind inclined retaining walls by Shukla (2015) is used in the present studyto obtain the design charts in non-dimensional form. Different field parameters related with wall geometry, seismic loadings,tension cracks, soil backfill properties, surcharge and wall friction are used in the present analysis. The present study hasquantified the effect of negative and positive wall inclination as well as the effect of soil cohesion (c), angle of shearingresistance (ϕ), surcharge loading (q) and the horizontal and vertical seismic coefficient (kh and kv) on seismic active earthpressure with the help of design charts for c-ϕ soil backfill. The design charts presented here in non-dimensional form aresimple to use and can be implemented by field engineers for design of inclined retaining walls under seismic conditions. Theactive earth pressure coefficients for cohesionless soil backfill achieved from the present study are validated with studiesreported in the literature.

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