STABILITY OF WATERFRONT RETAINING WALL SUBJECTED TO PSEUDO-DYNAMIC EARTHQUAKE FORCES AND TSUNAMI

2008 ◽  
Vol 02 (02) ◽  
pp. 107-131 ◽  
Author(s):  
SYED MOHD. AHMAD ◽  
DEEPANKAR CHOUDHURY
Keyword(s):  
Sliding Mode ◽  
Tsunami Wave ◽  
Limit Equilibrium ◽  
Retaining Wall ◽  
Earth Pressure ◽  
Inertia Force ◽  
Dynamic Approach ◽  
Modes Of Failure ◽  
Mode Of Failure ◽  
The Stability

The paper pertains to a study in which the waterfront retaining wall has been analyzed for its stability when it is exposed to the forces jointly coming from an earthquake and tsunami. Closed form solutions following the simple limit equilibrium principles have been proposed. For the calculation of the seismic passive earth pressure and the wall inertia force, pseudo-dynamic approach has been considered, while the hydrodynamic and the tsunami wave pressures have been calculated using different approximating solutions available in literature. The results presented in the sliding and overturning modes of failure of the wall show that the stability of the wall gets seriously challenged when it gets jointly exposed to the effects of the tsunami and earthquake. About 92% decrease is observed in the value of the factor of safety in sliding mode of failure of the wall as the ratio of tsunami wave height to the upstream still water height increases from 0 to 1.5. Also, the critical mode of failure of the wall has been found to be that of the overturning. Effect of different parameters involved in the analysis has also been studied and it has been observed that quite a few of them like kh, kv, ϕ, δ, ru have a significant effect on the stability of the wall. Comparison with a previously existing methodology using pseudo-static approach suggests that the present pseudo-dynamic approach is more realistic and comparatively less conservative and hence can be used as a handy simple economic method for the design of the waterfront retaining walls exposed to the combined effects of earthquake and tsunami.

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;

scholarly journals Stability Assessment of Earth Retaining Structures under Static and Seismic Conditions

2019 ◽  
Vol 4 (2) ◽  
pp. 15
Author(s):  
Nimbalkar ◽  
Pain ◽  
Ahmad ◽  
Chen
Keyword(s):  
Retaining Wall ◽  
Earth Pressure ◽  
Accurate Estimation ◽  
Engineering Practice ◽  
Active Earth Pressure ◽  
Stability Assessment ◽  
Linear Distribution ◽  
Backfill Soil ◽  
The Stability ◽  
Seismic Earth Pressure

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.

scholarly journals Analysis of passive earth pressure modification due to seepage flow effects

2018 ◽  
Vol 55 (5) ◽  
pp. 666-679 ◽  
Author(s):  
Z. Hu ◽  
Z.X. Yang ◽  
S.P. Wilkinson
Keyword(s):  
Limit Equilibrium ◽  
Retaining Wall ◽  
Reaction Force ◽  
Earth Pressure ◽  
Failure Surface ◽  
Friction Angle ◽  
Seepage Flow ◽  
Fourier Series Expansion ◽  
Passive Earth Pressure ◽  
Interface Friction

Using an assumed vertical retaining wall with a drainage system along the soil–structure interface, this paper analyses the effect of anisotropic seepage flow on the development of passive earth pressure. Extremely unfavourable seepage flow inside the backfill, perhaps due to heavy rainfall, will dramatically increase active earth pressure while reducing passive earth pressure, thus increasing the probability of instability of the retaining structure. A trial and error analysis based on limit equilibrium is applied to identify the optimum failure surface. The flow field is computed using Fourier series expansion, and the effective reaction force along the curved failure surface is obtained by solving a modified Kötter equation considering the effect of seepage flow. This approach correlates well with other existing results. For small values of both the internal friction angle and interface friction angle, the failure surface can be appropriately simplified with a planar approximation. A parametric study indicates that the degree of anisotropic seepage flow affects the resulting passive earth pressure. In addition, incremental increases in the effective friction angle and interface friction angle both lead to an increase in passive earth pressure.

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 Review on “Assessment of the effect of lateral dynamic forces on rcc cantilever l-shaped and t-shaped retaining wall with height variations”

2021 ◽  
Vol 1197 (1) ◽  
pp. 012030
Author(s):  
Jayesh Harode ◽  
Kuldeep Dabhekar ◽  
P.Y. Pawade ◽  
Isha Khedikar
Keyword(s):  
Retaining Wall ◽  
Earth Pressure ◽  
Bending Moment ◽  
Retaining Walls ◽  
Wall Material ◽  
Dynamic Forces ◽  
Present Design ◽  
Cantilever Retaining Walls ◽  
The Stability ◽  
Manual Calculation

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.

scholarly journals Arching Effect and Displacement on Theoretical Estimation for Lateral Force Acting on Retaining Wall

2021 ◽  
Author(s):  
Jun-feng Jiang ◽  
Qi-hua Zhao ◽  
Shuairun Zhu ◽  
Sheqin Peng ◽  
Yonghong Wu
Keyword(s):  
Limit Equilibrium ◽  
Retaining Wall ◽  
Earth Pressure ◽  
Friction Angle ◽  
Cohesionless Soil ◽  
Active Earth Pressure ◽  
Theoretical Methods ◽  
Arching Effect ◽  
Comparison Results ◽  
Tension Cracks

Abstract A new approach is proposed to evaluate the non-limit active earth pressure in cohesive-frictional based on the horizontal slices method and limit equilibrium method. This approach takes into account the arching effect, displacement, average shear stress of the soil slice, rupture angle and tension cracks. The accuracy of the proposed method is demonstrated by comparing the experimental results and other theoretical methods. The comparison results show that the proposed approach is suitable for calculating the non-limit active earth pressure in cohesive-frictional soil and cohesionless soil. Additionally, the empirical formulations of the mobilized internal friction angle and soil-wall interface friction angle usually used to cohesionless soil are still applied to cohesive-frictional soil through comparison calculated results of other theoretical methods and finite element method. Some valid formulations of the rupture angle and tension cracks were derived considering the cohesion, wall height, and unit weight.

scholarly journals Study on Passive Earth Pressure of Retaining Wall in Transversely Isotropic Soil

2020 ◽  
Vol 143 ◽  
pp. 01020
Author(s):  
Tao Chen ◽  
Chao Chen ◽  
Fengting Guan ◽  
Ruoyang Zhou
Keyword(s):  
Limit Equilibrium ◽  
Retaining Wall ◽  
Transverse Isotropy ◽  
Earth Pressure ◽  
Transversely Isotropic ◽  
Least Square Method ◽  
Least Square ◽  
Passive Earth Pressure ◽  
Principal Stress Direction ◽  
Tensor Theory

Based on the fabric tensor theory and the principle of least square method, the method of block processing in the same model to explore the variation of the passive earth pressure of the transversely isotropic soil was used in the study. At the same time, primary displacement application and multiple displacement application were applied to change the angle between the large principal stress direction of the filling and the normal direction of the deposition surface to obtain the new strength parameters ci and φi of each block after the model was divided and additionally analyzing the variation of the anisotropic passive earth pressure. The study shows: 1.Considering the transverse isotropy of the soil and reaching the limit equilibrium, the passive earth pressure of the soil after multiple displacement application is not only smaller than that after primary displacement application but also closed to the theoretical solution of Coulomb’s earth pressure; 2.When the soil is inclined, the anisotropy is significant when compared with the horizontal direction.

Analytic solutions of rupture angle in coulomb's earth pressure theory

2013 ◽  
Vol 10 (6) ◽  
pp. 573-576
Author(s):  
Zhiguang Guo ◽  
Guoyong Cheng ◽  
Fan Wang
Keyword(s):  
Limit Equilibrium ◽  
Retaining Wall ◽  
Numerical Test ◽  
Engineering Application ◽  
Earth Pressure ◽  
Reference Value ◽  
Failure Surface ◽  
Analytic Solutions ◽  
Foundation Pit ◽  
Simplified Solution

Coulomb's earth pressure theory is widely used in foundation pit supporting structure and retaining wall design, and Rupture angle is one of the key parameters in determining the failure surface location and the foundation pit influence scope. But there is no explicit formula of rupture angle or some wrong in existing formula. This paper, according to the limit equilibrium condition of slide wedge, obtained the analytical expression of Rupture angle which is the most simplified form in the current information. Through the numerical test this simplified solution is consistent with coulomb theory. The conclusion of this paper has some reference value in engineering application of coulomb theory.

scholarly journals Calculation of Active Earth Pressure for Narrow Backfill with a Curved Slip Surface

2019 ◽  
Vol 2019 ◽  
pp. 1-10
Author(s):  
Zhihui Wang ◽  
Aixiang Wu ◽  
Yiming Wang
Keyword(s):  
Equilibrium Equation ◽  
Slip Surface ◽  
Limit Equilibrium ◽  
Retaining Wall ◽  
Earth Pressure ◽  
Failure Surface ◽  
Friction Angle ◽  
Force Balance ◽  
Vertical Force ◽  
The Earth

A method was proposed to calculate the earth pressure from a cohesionless backfill with a high aspect ratio (ratio of height to width of retaining wall). An exponential equation of slip surface was proposed first. The proposed nonlinear slip surface equation can be obtained once the width and height of the backfill as well as the internal friction angle of the backfill were given. The failure surface from the proposed formula agreed well with the experimental slip surface. Then, the earth pressure was calculated using a simplified equilibrium equation based on the proposed slip surface. It is assumed that the minor principal stress of the backfill near the wall and at its corresponding slip surface where the depth is the same is the same. Thus, based on the vertical force balance of the horizontal backfill strip, assuming the wall-soil interface and the slip surface is in the limit equilibrium state, defined by the Mohr–Coulomb criterion, the differential equilibrium equation was obtained and numerically solved. The calculated results agreed well with the test data from the published literature.

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