scholarly journals ENSURING THE STABILITY OF RETAINED WALLS IN SEISMIC AREAS TAKING INTO ACCOUNT THE BACKFILL SOIL CONDITIONS

Author(s):  
Zh.S. Bekbolotova ◽  
S.V. Krylova ◽  
R.D. Tokoev

During earthquakes retaining walls are exposed to combined action. The retaining walls in seismic areas must account for the displacements, for resistance to failure in bearing, sliding and overturning. Research model have to estimate to dynamic the combined action of sliding and rocking and takes into consideration, non-linear soil stiffness in sliding, and rocking, geometrical and material damping in sliding, and rocking, and coupling effects. The calculation of the retaining wall is given, the design and the method of strengthening the structure at large deformations are shown.

2011 ◽  
Vol 243-249 ◽  
pp. 959-962
Author(s):  
De Ling Wang ◽  
Li Guo

In this paper, the force against rigid retaining walls from backfill soil under static loads and vibration loads is analyzed within three cases. The first case is an ordinary retaining wall without expanded polystyrene (EPS) geofoam buffer. In the second and the third case, a layer of vertical EPS buffer with different density and elastic modulus is placed between a rigid retaining wall and backfill soil. Numerical simulation results show that the force against the same retaining wall in the treated cases is less than that in the untreated case, under both static loads and vibration loads. Moreover, the compression of different EPS buffer is studied. Under vibration excitation, when the density and elastic modulus of EPS buffer decreases, its compression increases and more wall force is mitigated. Simulation results accord with the physical shaking table test data. Numerical results and physical test demonstrate that EPS geofoam seismic buffers hold great promise to reduce loads against rigid retaining wall structures, especially earthquake-induced dynamic loads.


2019 ◽  
Vol 4 (2) ◽  
pp. 15
Author(s):  
Nimbalkar ◽  
Pain ◽  
Ahmad ◽  
Chen

An accurate estimation of static and seismic earth pressures is extremely important in geotechnical design. The conventional Coulomb’s approach and Mononobe-Okabe’s approach have been widely used in engineering practice. However, the latter approach provides the linear distribution of seismic earth pressure behind a retaining wall in an approximate way. Therefore, the pseudo-dynamic method can be used to compute the distribution of seismic active earth pressure in a more realistic manner. The effect of wall and soil inertia must be considered for the design of a retaining wall under seismic conditions. The method proposed considers the propagation of shear and primary waves through the backfill soil and the retaining wall due to seismic excitation. The crude estimate of finding the approximate seismic acceleration makes the pseudo-static approach often unreliable to adopt in the stability assessment of retaining walls. The predictions of the active earth pressure using Coulomb theory are not consistent with the laboratory results to the development of arching in the backfill soil. A new method is proposed to compute the active earth pressure acting on the backface of a rigid retaining wall undergoing horizontal translation. The predictions of the proposed method are verified against results of laboratory tests as well as the results from other methods proposed in the past.


2014 ◽  
Vol 488-489 ◽  
pp. 354-358
Author(s):  
Li Yan Wang ◽  
Xiao Lei Du ◽  
Fu Xing Zhang ◽  
Rong Qiu Xue

For the geo-grid reinforced retaining wall, the reinforcement mechanism of seismic behavior is unclear, and there is no reasonable standard for seismic design. A non-linear finite difference method which is based on Lagrange method was applied to analyze internal reinforcement force of geo-grid under different design parameters. The elastic-plastic model is simulated to backfill soil and foundation, and the coupled elastic parameters are used to describe the interaction of soil and geo-grid. The design parameters include geo-grid reinforcement spacing, reinforcement length, backfill soil stiffness, and thickness of panel. Some distribution characters and sensitive parameters to the internal reinforcement force of geo-grid were achieved, which will be helpful to the seismic design of geo-grid reinforced soil retaining wall with integral panel.


2020 ◽  
pp. 65-75
Author(s):  
Liudmyla Skochko ◽  
Viktor Nosenko ◽  
Vasyl Pidlutskyi ◽  
Oleksandr Gavryliuk

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.


CERUCUK ◽  
2021 ◽  
Vol 5 (1) ◽  
pp. 69
Author(s):  
Adelina Melati Sukma

On the construction of green open space Jl. Kinibalu Banjarbaru There is a 6 meters tall slope beneath which the river is lined up during the rainy season and makes the slope exposed by water plus the absence of load or traffic on it make the pore figures on the land is large. Therefore, for protection reason, there is a soil alignment in the construction of soil retaining walls. The planned ground retaining wall type is cantilever and gabion. The stability analysis of the ground retaining walls is done manually and with the help of the Geoslope/W 2018 software. The value of the stability of the style against the bolsters, sliding, and carrying capacity of the soil using manual calculations for cantilever type and Netlon qualifies SNI 8460:2017. And for the overall stability calculation using Geoslope/W 2018 software obtained safety factor (SF) > 1.5. From the analysis, the design of planning can be used because it is safe against the dangers of avalanche.


2021 ◽  
Vol 1197 (1) ◽  
pp. 012030
Author(s):  
Jayesh Harode ◽  
Kuldeep Dabhekar ◽  
P.Y. Pawade ◽  
Isha Khedikar

Abstract It is now becoming very essential to analyse the behaviour of retaining structures due to their wide infrastructural applications. The important factors which are affecting the stability of the retaining wall are the distribution of earth pressure on the wall, material of backfill & its reaction against earth pressure. There are several types of retaining walls, out of them the cantilever retaining wall is adopted for present design and study. In this paper, the study of literature based on the design of the cantilever retaining walls under seismic or dynamic conditions is studied. From the studied literature, many authors performed their calculations in Excel sheets by a manual method. Then the Results obtained from the manual calculation are then validated in STAAD pro. Several authors show the calculated quantity of steel and concrete required for various heights of walls. It is also concluded from the study that the design of cantilever retaining wall is suitable, safe, and economical up to a height of 6m, after that banding moment at toe increases. Some authors have also shown the calculated factor of safety for different height conditions. From the study of mentioned literature, we can recommended to also show the graph of bending moment with height variation. Both the designs are done for various heights ranging from 3 m to 6 m.


2014 ◽  
Vol 971-973 ◽  
pp. 2141-2146
Author(s):  
Tian Zhong Ma ◽  
Yan Peng Zhu

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;


2019 ◽  
Vol 5 (2) ◽  
Author(s):  
A'isyah Salimah ◽  
Muhammad Fathur Rouf Hasan ◽  
Suripto Suripto ◽  
Yelvi Yelvi ◽  
Imam H Sasongko

Permukaan tanah tidak semua berbentuk bidang datar, namun memiliki perbedaan ketinggian dan kemiringan pada setiap daerah. Perbedaan ketinggian tanah mampu mengakitbatkan terjadinya pergerakan tanah yaitu longsor. Keberadaan bangunan base transceiver station (BTS) tower di Desa Sukaresmi, Cisaat, Sukabumi yang berada pada daerah lereng curam dengan kondisi retaining wall dan pagar dalam keadaan retak dan mengalami penurunan tanah menjadi salah satu faktor yang mengancam keselamatan. Untuk mengantisipasi dampak kerusakan lingkungan bertambah parah dibutuhkan penanganan khusus. Penelitian ini bertujuan untuk melakukan analisis stabilitas dan perkuatan lereng menggunakan software Plaxis2D. Adapun metode penelitian dilakukan dengan melakukan investigasi lapangan secara langsung, pengujian laboratorium, analisis stabilitas perkuatan lereng dengan software Plaxis2D serta rekomendasi perbaikan drainase. Upaya perkuatan lereng dengan mengganti dan memperdalam retaining wall existing. Hasil perkuatan lereng dapat meningkatkan nilai safety factor menjadi 1,369, nilai ini lebih besar dari safety factor existing sebesar 1,302. Kata kunci: cisaat, longsor, Plaxis2D, stabilitas lereng. The soil surface is believed to have differences in height and slope in each region. The different elevation could cause land movements namely landslides. The existence of tower base transceiver station (BTS) buildings in Sukaresmi Village, Cisaat,  Sukabumi on a deep slope area with cracked retaining walls and fences condition which experienced settlement is one of the factors that threaten safety. To anticipate the impact of environmental damage getting worse requires special handling. The aim  of this study is to analyze the stability and slope reinforcement using Plaxis2D software. The research method is carried out by conducting direct field investigations, laboratory tests, reinforced slope stability analysis with Plaxis2D software and drainage refinement recommendations. Countermeasures to strengthen the slope are done by replacing and deepening the existing retaining wall. The result of this measure is the increase of the safety factor value to 1,369, this value is greater than the value of the existing safety factor of 1,302. Keywords : cisaat, landslide, Plaxis2D, slope stability.


2020 ◽  
Vol 30 (3) ◽  
pp. 214-233
Author(s):  
Fatima Zohra Benamara ◽  
Ammar Rouaiguia ◽  
Messaouda Bencheikh

Abstract Anchored retaining walls are structures designed to support different loading applied in static and dynamic cases. The purpose of this work is to design and study the stability of an anchored retaining wall loaded with different seismic actions to obtain minimal anchor lengths. Mononobe-Okabe theory has been applied for the evaluation of seismic earth pressures developed behind the anchored wall. Checking the dynamic stability of anchored retaining walls is usually done using the classic Kranz model. To take into consideration the effects of the internal forces developed during failure, we have proposed a new model, based on the Kranz model, which will be used as the Kranz model to find the critical angle failure performed iteratively until the required horizontal anchor length is reached for a minimum safety factor. The results of this study confirm that the effect of the seismic load on the design of an anchored retaining wall, and its stability, has a considerable influence on the estimation of anchor lengths. To validate the modifications made to the new model, a numerical analysis was carried out using the Plaxis 2D software. The interpretation of the obtained results may provide more detailed explanation on the effect of seismic intensities for the design of anchored retaining walls.


2014 ◽  
Vol 7 (3) ◽  
pp. 1-24
Author(s):  
Safa Hussain Abid Awn ◽  
Waad Abdulsattar Zakaria

Retaining walls may be required in a location where gypsum may present in soil in large percentages .The behavior of retaining walls on ordinary soils is well known but the behavior of retaining walls resting on gypseons soils may be not well understood as the case of ordinary soils.In this study it is intended to reflect the behavior of gravity retaining wall resting on collapsible soil. And to do so a small prototype model (600mm*500mm*200mm) is used with soil mixed in presumed percentages with different gypsum percentages (5%, 20%, 30%, 50%). In addition to a model with 30% gypsum and treated with 2.7% Cement dust mixed with soil founded retaining wall structure. After preparing the foundation gypseous soil, a small glass made retaining wall filled with sand, which represent gravity wall, is put over such bed and backfilled with ordinary sandy soil. Dial gauges are placed to side and top of wall to measure the rotation settlement behavior and collapse of system. 4kPa stress are applied to backfill soil as to accelerate collapse with leaching process commenced. Data are recorded and analyzed completely, which shows the behavior of such structures embedded with different gypsum content.The improvement in rotation settlement and collapse for the retaining wall model reaches more than 89%, was gained after treating the embedded gypseous soil layer, with 2.7% cement dust.


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