scholarly journals The effect of the setback angle on overturning stability of the retaining wall

2021 ◽  
Vol 72 (1) ◽  
pp. 66-75
Author(s):  
Nguyen Thi Thu Nga ◽  
Ngo Van Thuc ◽  
Lam Thanh Quang Khai ◽  
Nguyen Thanh Trung
Keyword(s):  
Cross Sections ◽  
Retaining Wall ◽  
Friction Angle ◽  
Key Factors ◽  
Construction Costs ◽  
Technical Requirements ◽  
Overturning Stability ◽  
Natural Terrain ◽  
The Stability ◽  
Selection Of

Retaining walls are a relatively common type of protective structure in construction to hold soil behind them. The form of the retaining wall is also relatively diverse with changing setback angle. Design cross-selection of retaining wall virtually ensures the stability of the retaining wall depends on many aspects. It is essential to consider these to bring the overall picture. For this reason, the authors selected a research paper on the influence of the setback angle on the overturning stability of the retaining wall. To evaluate the behavior stability of retaining wall with some key factors having different levels such as setback angle, internal friction angle of the soil, the slope of the backfill is based on the design of the experiment (DOE) with useful statistical analysis tools. These, proposing the necessary technical requirements in choosing significant cross-sections of retaining structure to suit natural terrain and save construction costs, ensure safety for the project.

scholarly journals Levee reliability analyses for various flood return periods – a case study in southern Taiwan

2015 ◽  
Vol 15 (4) ◽  
pp. 919-930 ◽  
Author(s):  
W.-C. Huang ◽  
H.-W. Yu ◽  
M.-C. Weng
Keyword(s):  
Water Level ◽  
Cross Sections ◽  
Retaining Wall ◽  
Failure Mechanisms ◽  
Friction Angle ◽  
Return Periods ◽  
Scouring Depth ◽  
Southern Taiwan ◽  
Potential Failure

Abstract. In recent years, heavy rainfall conditions have caused disasters around the world. To prevent losses by floods, levees have often been constructed in inundation-prone areas. This study performed reliability analyses for the Chiuliao First Levee in southern Taiwan. The failure-related parameters were the water level, the scouring depth, and the in situ friction angle. Three major failure mechanisms were considered: the slope sliding failure of the levee and the sliding and overturning failures of the retaining wall. When the variability of the in situ friction angle and the scouring depth are considered for various flood return periods, the variations of the factor of safety for the different failure mechanisms show that the retaining wall sliding and overturning failures are more sensitive to the change of the friction angle. When the flood return period is greater than 2 years, the levee could fail with slope sliding for all values of the water level difference. The results of levee stability analysis considering the variability of different parameters could aid engineers in designing the levee cross sections, especially with potential failure mechanisms in mind.

Performance of cement-stabilized retaining walls

2005 ◽  
Vol 42 (3) ◽  
pp. 876-891 ◽  
Author(s):  
M A Ismail
Keyword(s):  
Finite Element ◽  
Retaining Wall ◽  
Friction Angle ◽  
Experimental Program ◽  
Centrifuge Model Test ◽  
Element Analysis ◽  
Centrifuge Testing ◽  
Load Carrying ◽  
The Stability ◽  
Surrounding Soil

This paper investigates the performance of a cement-stabilized retaining wall as a potentially economic solution for supporting vertical cuts in roads and embankments. This investigation was carried out through a comprehensive numerical and experimental program in which the stabilized wall was treated as a c′–ϕ soil. To optimize the design of the stabilized wall, a plane-strain finite element analysis was carried out, using the PLAXIS code, in a parametric study that varied the wall geometry and the shear strength parameters for both the wall and its surrounding soil. The performance of the stabilized retaining wall was verified by a centrifuge model test carried out at an equivalent acceleration of 67g for a sand treated with 3% Portland cement. The results have shown that the load-carrying capacity of the wall is affected primarily by both the cementation of the wall and the friction angle of the surrounding soil. There exists a threshold of cementation beyond which the stability does not increase when the failure mechanism is located completely inside the in situ soil. This critical cementation appears to be a crucial factor in maintaining an economic design for this type of wall. Centrifuge test results confirmed the satisfactory behaviour of cement-stabilized retaining walls.Key words: cement stabilization, retaining wall, cohesion, finite element, centrifuge testing.

The Stability Analysis of Reinforced Earth Retaining Wall System and the Study of its Reinforcement Optimization

2011 ◽  
Vol 90-93 ◽  
pp. 2389-2392
Author(s):  
Hai Yan Ju ◽  
Gui Qing Gao ◽  
Jian Hua Li ◽  
Jiang Qian Zhao ◽  
Zhang Ming Li
Keyword(s):  
Cross Sections ◽  
Design Method ◽  
Retaining Wall ◽  
Physical Behavior ◽  
Reinforced Earth ◽  
Slope Treatment ◽  
The Stability ◽  
Relationship Of ◽  
The Relationship ◽  
System Program

Because the relationship is not considered between physical behavior and cross sections of bars, the conventional reinforced earth retaining wall design based on constant value would lead to some limitations: the haul-resistant coefficient of the top wall is not enough, but it goes beyond at the bottom of retaining wall. In the paper, considering the SARMA method, based on computing formula of traditional slope stability, the detailed programme is realized by the language of FORTRAN, it can make up deficiency that lies in the tradition reinforced earth retaining wall by considering the relationship of physical behavior and cross sections, lengths and layers of bars. Finally, the system program has been applied to a slope treatment project in Guangzhou. Compared with the design method of traditional regulations, it is demonstrated that the optimum length required is obtained, the cross section and length of bars are fully used, and the design is simplified.

scholarly journals Influence of parameters of retaining walls and loose soils on the stability of slopes in the new construction of residential complexes

2020 ◽  
pp. 65-75
Author(s):  
Liudmyla Skochko ◽  
Viktor Nosenko ◽  
Vasyl Pidlutskyi ◽  
Oleksandr Gavryliuk
Keyword(s):  
Finite Element ◽  
Slope Stability ◽  
Cross Sections ◽  
Retaining Wall ◽  
Retaining Walls ◽  
Natural State ◽  
Soil Parameters ◽  
Stability Of Slopes ◽  
The Stability ◽  
Stage 1

The stability of the slope in the existing and design provisions is investigated, the constructive decisions of retaining walls on protection of the territory of construction of a residential complex in a zone of a slope are substantiated. The stability of the slope when using rational landslide structures is estimated. The results of the calculation of the slope stability for five characteristic sections on the basis of engineering-geological survey are analyzed. For each of the given sections the finite-element scheme according to the last data on change of a relief is created. The slope was formed artificially by filling the existing ravine with construction debris from the demolition of old houses and from the excavation of ditches for the first houses of the complex. Five sections along the slope are considered and its stability in the natural state and design positions is determined. Also the constructive decisions of retaining walls on protection of the territory of construction of a residential complex as along the slope there are bulk soils with various difference of heights are substantiated. This requires a separate approach to the choice of parameters of retaining walls, namely the dimensions of the piles and their mutual placement, as well as the choice of the angle of the bulk soil along the slope. The calculations were performed using numerical simulation of the stress-strain state of the system "slope soils-retaining wall" using the finite element method. An elastic-plastic model of soil deformation with a change in soil parameters (deformation module) depending on the level of stresses in the soil is adopted. Hardening soil model (HSM) used. Calculations of slope stability involve taking into account the technological sequence of erection of retaining walls and modeling of the phased development of the pit. The simulation was performed in several stages: Stage 1 - determination of stresses from the own shaft, Stage 2 - assessment of slope stability before construction, Stage 3 - installation of retaining wall piles, Stage 4 - assessment of slope stability after landslides. Based on these studies, practical recommendations were developed for the design of each section of the retaining wall in accordance with the characteristic cross-sections.

scholarly journals Levee reliability analyses for various flood return periods – a case study in Southern Taiwan

2015 ◽  
Vol 3 (1) ◽  
pp. 457-495
Author(s):  
W.-C. Huang ◽  
H.-W. Yu ◽  
M.-C. Weng
Keyword(s):  
Water Level ◽  
Cross Sections ◽  
Retaining Wall ◽  
Failure Mechanisms ◽  
Friction Angle ◽  
Return Periods ◽  
Scouring Depth ◽  
Southern Taiwan ◽  
Potential Failure

Abstract. In recent years, heavy rainfall conditions have caused damages around the world. To prevent damages by floods, levees have often been constructed in prone-to-inundation areas. This study performed reliability analyses for the Chiuliao 1st Levee located in southern Taiwan. The failure-related parameters were the water level, the scouring depth, and the in-situ friction angle. Three major failure mechanisms were considered, including the slope sliding failure of the levee, and the sliding and overturning failures of the retaining wall. When the variabilities of the in-situ friction angle and the scouring depth are considered for various flood return periods, the variations of the factor of safety (FS) for the different failure mechanisms show that the retaining wall sliding and overturning failures are more sensitive to the variability of the friction angle. When the flood return period is greater than 2 years, the levee can undergo slope sliding failure for all values of the water level difference. The results for levee stability analysis considering the variability of different parameters could assist engineers in designing the levee cross sections, especially with potential failure mechanisms in mind.

scholarly journals Stability of Reinforced Retaining Wall under Seismic Loads

2019 ◽  
Vol 9 (11) ◽  
pp. 2175 ◽  
Author(s):  
Liang Jia ◽  
Shikai He ◽  
Na Li ◽  
Wei Wang ◽  
Kai Yao
Keyword(s):  
Slip Surface ◽  
Retaining Wall ◽  
Tensile Force ◽  
Friction Angle ◽  
Unit Weight ◽  
Seismic Load ◽  
Seismic Loads ◽  
The Stability ◽  
Slice Method ◽  
Reinforced Retaining Wall

Based on the horizontal slice method (HSM) and assuming a log spiral slip surface, a method to analyze the stability of a reinforced retaining wall under seismic loads was established in this study by calculating the tensile force of the reinforcement. A parametric study was conducted on the normalized tensile force of the reinforcement, and it was observed that the normalized tensile force tends to increase with acceleration of the seismic load and the height of the backfill. Moreover, it also increases with soil unit weight, while it decreases with increased friction angle of the backfill soil, and the influence of soil cohesion on the normalized tensile force is not significant. The HSM method is proved to be suitable for analyzing the tensile force of reinforcement in retaining walls under seismic loads.

Seismic Strengthening Methods and Analysis of Instability of Gravity Retaining Walls

2014 ◽  
Vol 971-973 ◽  
pp. 2141-2146
Author(s):  
Tian Zhong Ma ◽  
Yan Peng Zhu
Keyword(s):  
Safety Factor ◽  
Limit Equilibrium ◽  
Retaining Wall ◽  
Earth Pressure ◽  
Retaining Walls ◽  
Theoretical Formula ◽  
Seismic Strengthening ◽  
Gravity Retaining Wall ◽  
Overturning Stability ◽  
The Stability

Using the frame supporting structure of pre-stressed anchor bolt seismic strengthening technology reinforced the instability of gravity retaining wall. Earth pressure of retaining wall in seismic reinforcement after shall take between active and static earth pressure for the form of the distribution . In this paper, based on the limit equilibrium theory, and the whole stability for retaining walls is analysis, the theoretical formula of the stability safety factor between stability against slope and overturning safety factor is derived. By calculation and comparative analysis with an example, the stability safety factor of gravity retaining wall with introducing this strengthening technology is improved obviously. Keywords: frame anchor structure; seismic strengthening; anti-slip and anti-overturning; stability coefficient;

Reliability analysis of the anti-sliding of a retaining wall subjected to seismic loads

2021 ◽  
pp. 1748006X2096428
Author(s):  
Xiao-Cheng Huang ◽  
Xiao-Di Xu ◽  
Qiu-Nan Chen ◽  
Yun-Fu Liu
Keyword(s):  
Reliability Analysis ◽  
Spatial Correlation ◽  
Retaining Wall ◽  
Friction Angle ◽  
Numerical Results ◽  
Seismic Loads ◽  
Full Agreement ◽  
Reliability Based Design ◽  
Complementary Role ◽  
The Stability

Geotechnical engineering involves various types of uncertainties, as it always deals with highly variable natural materials. Reliability-based design/analysis can play at least a complementary role in the design approach. In this paper, reliability analysis of anti-sliding of retaining wall with the parameters treated as random variables is performed based on the concept of random fields. Both friction angle and cohesion of soils near the interface along the base of retaining wall are treated as Gaussian fields. The spatial correlation and cross correlation of the variables are calculated by a specific covariance function and the seismic loads act on retaining walls are also taken into account. Examples are illustrated to verify the accuracy of the proposed approach. It is found from the numerical results that the spatial correlation of shear strength has an important influence on the probability of the anti-sliding failure of retaining wall. Moreover, the numerical results obtained from the proposed method are in full agreement with those obtained from Monte Carlo simulations. Therefore, the proposed method provides a new view to study the stability of a retaining wall subjected to seismic loads.

scholarly journals ANALISIS STABILITAS DINDING PENAHAN TANAH DENGAN PERKUATAN BRONJONG PADA JALAN TOL ULUJAMI – PONDOK RANJI RAMP BINTARO VIADUCT

2019 ◽  
Vol 1 (1) ◽  
pp. 91-100
Author(s):  
Maria Febe ◽  
Imam Hariadi Sasongko
Keyword(s):  
Bearing Capacity ◽  
Safety Factor ◽  
Soil Structure ◽  
Retaining Wall ◽  
Stability Calculation ◽  
The Road ◽  
Toll Road ◽  
Overturning Stability ◽  
Capacity Calculation ◽  
The Stability

Pada Jalan Tol Ulujami – Pondok Ranji STA 03+150 terdapat sebuah jembatan yang opritnya mengalami penurunan yang menyebabkan ketidaknyamanan saat melintas di bahu jalannya. Penyebab penurunan tersebut diduga akibat adanya pergerakan struktur tanah bawah jalan sehingga menimbulkan terjadinya ketidakstabilan bangunan diatasnya. Tujuan studi adalah untuk mengetahui nilai faktor keamanan dinding penahan tanah dengan perkuatan bronjong terhadap kelongsoran, stabilitas geser, guling, dan daya dukung tanah, serta penurunan. Perhitungan tekanan tanah dinding ini menggunakan Teori Rankine. Untuk perhitungan stabilitas terhadap daya dukung tanah menggunakan persamaan Terzaghi. Perhitungan stabilitas dinding terhadap kelongsoran menggunakan metode Fellenius dan perangkat lunak Plaxis 8.6. Penurunan yang dihitung adalah penurunan konsolidasi primer dan sekunder. Hasil perhitungan stabilitas pada dinding penahan gravitasi didapatkan bahwa dimensi dinding tersebut tidak aman terhadap geser dan guling yaitu Fgl = 0,110 ≤ 1,5 dan Fgs = 0,205 ≤ 1,5. Serta penurunan yang terjadi sebesar 57,8 cm selama 62,704 tahun. Dari hasil perhitungan faktor keamanan stabilitas guling dan geser pada dinding penahan gravitasi tersebut, maka direncanakan perbesaran dimensi dinding agar aman terhadap geser dan guling. Didapati faktor keamanannya terhadap geser dan guling menjadi Fgs = 2,225 ≥ 1,5 dan Fgl = 1,740 ≥ 1,5.Kata kunci: dinding penahan tanah, bronjong, stabilitas dinding penahan tanah Bridge at STA 03+150 Ulujami – Pondok Ranji toll road has an approach settlement reduces its service and traffic may disturbed significantly. Settlement probably triggered by soil structure movement at the bottom of the road. The instability occurred and finally structure above damaged. The aim of the study was to calculate the safety factor of retaining wall strengthened with gabion against sliding, shear, overturning, and bearing capacity failure as well as its settlement. The calculation of safety factor against shear and overtuning conducted using Rankine Theory, while bearing capacity calculation done by uses Terzaghi. Calculations of sliding using Fellenius method and Plaxis 8.6 software. The writer also calculate settlement, both at primary and secondary consolidations. The results of stability calculation of gravity wall were as follows: safety factor against overtuning was 0,110 and shear 0,205 respectively, while settlement was 57,8 cm for 62,704 years. After the calculation mention above, in which all of the aspects calculated was not safe, the gravity wall then be redesigned as seen in the figure and the stability increase become 2,225 for shear 1,740 for overturning stability respectively. Using minimum allowable safety factor as 1,5 for all calculations, the gravity wall is now safe.Keywords: retaining walls, gabion, stability of retaining wall

An Analysis of Dissociation of Molecules in a High Resolution Electron Microscope

1973 ◽  
Vol 31 ◽  
pp. 486-487
Author(s):  
Mihir Parikh
Keyword(s):  
Electron Microscope ◽  
High Resolution ◽  
Cross Sections ◽  
Resolving Power ◽  
Peak Intensity ◽  
Molecular Film ◽  
Resolution Electron ◽  
Dissociation Cross Section ◽  
High Resolution Electron Microscope ◽  
The Stability

It is well known that the resolution of bio-molecules in a high resolution electron microscope depends not just on the physical resolving power of the instrument, but also on the stability of these molecules under the electron beam. Experimentally, the damage to the bio-molecules is commo ly monitored by the decrease in the intensity of the diffraction pattern, or more quantitatively by the decrease in the peaks of an energy loss spectrum. In the latter case the exposure, EC, to decrease the peak intensity from IO to I’O can be related to the molecular dissociation cross-section, σD, by EC = ℓn(IO /I’O) /ℓD. Qu ntitative data on damage cross-sections are just being reported, However, the microscopist needs to know the explicit dependence of damage on: (1) the molecular properties, (2) the density and characteristics of the molecular film and that of the support film, if any, (3) the temperature of the molecular film and (4) certain characteristics of the electron microscope used

Sign in / Sign up

Export Citation Format

Share Document