Pseudo-static lateral earth pressures on broken-back retaining walls

2010 ◽  
Vol 47 (11) ◽  
pp. 1247-1258 ◽  
Author(s):  
Abouzar Sadrekarimi

Displacement of retaining walls during earthquakes causes damage to the structures founded on their backfill. The displacement of the wall can be reduced by decreasing the lateral earth pressure applied on its back. This can be achieved in a broken-back wall as the size of the failure wedge formed behind the wall is reduced; therefore, the calculation of lateral earth pressures is essential in assessing the safety of and designing broken-back retaining walls. In this study, a series of reduced-scale shaking table model experiments were performed on broken-back quay walls composed of concrete blocks with two different rear-face shapes. In comparison with a vertical-back wall, earth pressures increased at the upper forward (i.e., seaward) leaning rear-face segments of the wall, whereas they decreased at lower backward (i.e., landward) leaning elevations. Because of the wide application of the pseudo-static method of Mononobe–Okabe in engineering practice and design codes, lateral earth pressures have also been estimated using this approach. The comparison between the measured lateral earth pressures and those calculated using the Mononobe–Okabe method shows fairly good agreement in predicting the overall distribution of lateral active earth pressure during and after the shaking.

Retaining walls are structures used not only to retain earth but also water and other materials such as coal, ore, etc. where conditions do not permit the mass to assume its natural slope. In this chapter, after considering the types of retaining wall, earth pressure theories are developed in estimating the lateral pressure exerted by the soil on a retaining structure for at-rest, active, and passive cases. The effect of sloping backfill, wall friction, surcharge load, point loads, line loads, and strip loads are analyzed. Karl Culmann's graphical method can be used for determining both active and passive earth pressures. The analysis of braced excavations, sheet piles, and anchored sheet pile walls are considered and practical considerations in the design of retaining walls are treated. They include saturated backfill, wall friction, stability both external and internal, bearing capacity, and proportioning the dimensions of the retaining wall. Finally, a brief treatment of earth pressure on underground structures is included.


2013 ◽  
Vol 275-277 ◽  
pp. 269-272 ◽  
Author(s):  
Xi Yan Jiang ◽  
Zhan Xue Zhou

Based on the method of level-layer analysis , with the sliding harmonious condition of layered backfills considered , the theoretical answers to the unit earth pressures , the resultant earth pressures and the points of application of the resultant earth pressures on retaining walls with layered non-cohesive backfills are set up . The comparisons are made with Coulomb’s formula.


2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Changwei Yang ◽  
Jian Jing Zhang ◽  
Qu Honglue ◽  
Bi Junwei ◽  
Liu Feicheng

To ascertain seismic response of retaining wall in the Wenchuan earthquake, large shaking table tests are performed and an acceleration record is acted in 3 directions. In the tests, acceleration time history recorded at Wolong station in the Wenchuan earthquake is used to excite the model wall. Results from the tests show that the location of dynamic resultant earth pressure is 0.35–0.49 H from toe of the wall for road shoulder retaining wall on rock foundation, 0.33–0.42 H for embankment retaining wall on rock foundation, and 0.46–0.77 H for road shoulder retaining wall on soil foundation. Besides, dynamic earth pressure increases with the increase of ground shaking from 0.1 g to 0.9 g and the relationship is nonlinear. The distribution is closed to for PGA less than 0.4 g but larger for PGA larger than and equal to 0.4 g, especially on the soil foundation. After the comparison of measured earth pressures and theoretical results by pseudodynamic method and pseudostatic method, results of the former are consistent with those of the shaking table test, but results of the latter method are smaller than measured.


1998 ◽  
Vol 35 (4) ◽  
pp. 591-599 ◽  
Author(s):  
Zuyu Chen ◽  
Songmei Li

The generalized method of slices, commonly used in slope stability analysis, can be extended to determine active earth pressures applied to various types of supports. The governing force and moment equlibrium equations are given. In a similar manner to slope stability analysis, the methods of optimization are used to define the critical slip surface that is associated with the maximum wall pressure. Examples show that the approaches give active earth pressures identical to the Rankine solution for gravity walls. For other types of support, such as anchored or strutted walls, the earth pressure is determined by assigning appropriate locations of the point of application on the wall. It has been found that applying the restrictions of physical admissibility is more vital in earth pressure problems than in slope stability assessments.Key words: earth pressure, limit equilibrium method, the method of slices, retaining walls.


2021 ◽  
Vol 13 (1) ◽  
pp. 570-581
Author(s):  
Meriem F. Bouali ◽  
Mahdi O. Karkush ◽  
Mounir Bouassida

Abstract The general assumption of linear variation of earth pressures with depth on retaining structures is still controversial; investigations are yet required to determine those distributions of the passive earth pressure (PEP) accurately and deduce the corresponding centroid location. In particular, for rigid retaining walls, the calculation of PEP is strongly dependent on the type of wall movement. This paper presents a numerical analysis for studying the influence of wall movement on the PEP distribution on a rigid retaining wall and the passive earth thrust location. The numerical predictions are remarkably similar to existing experimental works as recorded on scaled test models and full-scale retaining walls. It is observed that the PEP varies linearly with depth for the horizontal translation, but it is nonlinear when the movement is rotational about the top of the retaining wall. When rotation is around the top of the wall, the resultant of PEP is located at a depth that varies between 0.164 and 0.259H of the wall height measured from the base of the wall, which is lesser than 1/3 of the wall height. The passive earth thrust location is highly affected by the soil–wall friction angle, especially when the friction angle of the backfill material increases. Despite the herein presented results, further experiments are recommended to assess the corresponding numerical predictions.


2010 ◽  
Vol 168-170 ◽  
pp. 200-205
Author(s):  
Fei Song ◽  
Jian Min Zhang ◽  
Lu Yu Zhang

The evaluation of earth pressure is of vital importance for the design of various retaining walls and infrastructures. Experimental studies show that earth pressures are closely related to the mode and amount of wall displacement. In this paper, based on the reveal of the formation mechanism of earth pressures against rigid retaining wall with RTT mode, a new method is proposed to calculate the earth pressure distribution in such conditions. Finally, the effectiveness of the method is confirmed by the experimental results.


1982 ◽  
Vol 19 (3) ◽  
pp. 213-224 ◽  
Author(s):  
W. F. Anderson ◽  
T. H. Hanna ◽  
D. A. Ponniah ◽  
S. A. Shah

Laboratory-scale tests simulating field construction procedures have been carried out to examine the behaviour of the soil–wall–anchor system when a rigid retaining wall, restrained by anchors, supports a sand backfill on which there is surface loading. Two main series of tests have been carried out, one with a uniform load applied over the whole backfill surface, and the other with a strip load applied parallel to the wall and at a varying distance from it. In both series of tests the intensity of loading was varied, and in the series with uniform loading on the backfill the effects of varying anchor inclination were studied. During all stages of construction wall movements, earth pressures, anchor loads, wall base reaction, and backfill surface subsidence were monitored. Although a conservative approach was used in the determination of the anchor loads, wall movements, and consequently backfill subsidence, were considerable. Similar movements at full scale could lead to settlement damage in a structure founded on a shallow mat or strip footings on a backfill, so tentative suggestions are made for more conservative earth pressure distribution assumptions for design purposes for the two cases studied.


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