Reinforcement Strain and Potential Failure Surface of Geogrid Reinforced Soil-Retaining Wall under Horizontal Seismic Loading

This paper presents experimental results from shaking table tests on two reduced-scale geogrid reinforced soil-retaining walls (RSRWs) constructed using standard soil, modular facing blocks, and uniaxial geogrid reinforcement to investigate the distribution of the geogrid strain and the mode of potential failure surface for dynamic loading conditions. Similitude relationships for shaking table tests in a 1 g gravitational field were used to scale the specimen geometry, applied characteristics of the earthquake motions. The lateral displacement of the top model is sufficiently large for the top-model block to fall down, and the RSRW is thus destroyed. The tensile strain at the lower part is greater than that at the upper part of the RSRW. The tensile strain in different layers for two-tiered RSRW is consistent with single-step RSRW. On comparing the measured maximum tensile strain lines of the geogrid with the result of the existing calculation method of the potential failure surface, it can be observed that the existing partial calculation method is conservative. Based on the calculation methods of various potential failure surfaces and the measured data, the use of a two-tiered fold-line failure surface is proposed for the two-tiered RSRW while taking into consideration the width of the platform. And it is advised that the failure surface calculation method of BS8006 be used as the calculation method for the potential failure surface of the single-step RSRW under dynamic motion.

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Investigation on the seismic response of geogrid reinforced soil walls backfilled with cement-fiber-treated soil through 1-g shaking table tests

Geosynthetics International ◽

10.1680/jgein.21.00019a ◽

2021 ◽

pp. 1-54

Author(s):

A.M. Safaee ◽

A. Mahboubi ◽

A. Noorzad

Keyword(s):

Lateral Displacement ◽

Deformation Mode ◽

Reinforced Soil ◽

Shaking Table ◽

Physical Models ◽

Shaking Table Tests ◽

Treated Soil ◽

Soil Walls ◽

Wall Models ◽

Improved Performance

Improving the characteristics of local low-strength soils at the construction site is one of the appropriate approaches to employ the soils as a backfill of geogrid reinforced soil (GRS) walls. In this study, the fiber-cement-treated sand-silt mixture was used as the backfill of walls. The post-earthquake performance of the walls was evaluated by applying the sinusoidal waves on 1-m high reduced-scale physical models and conducting a series of 1-g shaking table tests. A comparison of the wall models constructed with treated and untreated backfill indicated the advantages of geogrid-reinforced fiber-cement-treated soil walls subjected to strong ground motion. The results revealed the better behavior of the wall models backfilled with treated soil mixtures under dynamic loading. Such improved performance was more evident in (1) deformation responses, including the lateral displacement of wall facing, deformation mode, failure surfaces, and settlement of backfill surface and (2) acceleration response in different locations, including facing, reinforced, and retained zone of walls.

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Shaking Table Study on the Seismic Performance of Geogrid Reinforced Soil Retaining Walls

Advances in Civil Engineering ◽

10.1155/2021/6668713 ◽

2021 ◽

Vol 2021 ◽

pp. 1-16

Author(s):

Xiaoguang Cai ◽

Sihan Li ◽

Honglu Xu ◽

Liping Jing ◽

Xin Huang ◽

...

Keyword(s):

Friction Coefficient ◽

Fundamental Frequency ◽

Retaining Wall ◽

Failure Surface ◽

Reinforced Soil ◽

Shaking Table ◽

Seismic Load ◽

Peak Displacement ◽

Acceleration Amplification ◽

Reinforcement Strain

This study presents experimental results from shaking table tests on a reduced-scale geogrid reinforced soil retaining wall (RSRW) to investigate the seismic response of the fundamental frequency, acceleration amplification, face displacement, backfill surface settlement, and reinforcement strain under different peak accelerations and durations. The fundamental frequency is in good agreement with the predicted values. The root mean square (RMS) acceleration amplification factors increase nonlinearly with the wall height and decrease with increasing seismic load, which is not regarded as a constant value. The distributions of the peak displacement are consistent with those of the residual displacement. The combination of the sliding and rotation is observed as the predominant mode of displacement, and the rotation mode is dominant. The positions near the face (35 cm) and the ends of the reinforcement (140 cm) demonstrated larger settlement than that of the central position (70 cm and 105 cm). The reinforcement strain increased with increasing peak acceleration and maximum values measured at the central layers. The trends of the potential failure surface are similar to those of the 0.3H bilinear failure surface. The friction coefficient is nonlinearly distributed along with the reinforcements, and the maximum friction coefficient appears at the top layer (F11).

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Seismic response of wrap-faced reinforced soil-retaining wall models using shaking table tests

Geosynthetics International ◽

10.1680/gein.2007.14.6.355 ◽

2007 ◽

Vol 14 (6) ◽

pp. 355-364 ◽

Cited By ~ 44

Author(s):

A. Murali Krishna ◽

G. Madhavi Latha

Keyword(s):

Seismic Response ◽

Retaining Wall ◽

Reinforced Soil ◽

Shaking Table ◽

Shaking Table Tests ◽

Wall Models

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Seismic Response of Pile Groups Improved with Deep Cement mixing Columns in Liquefiable Sand: Shaking Table Tests

Canadian Geotechnical Journal ◽

10.1139/cgj-2020-0505 ◽

2021 ◽

Author(s):

Dingwen Zhang ◽

Anhui Wang ◽

Xuanming Ding

Keyword(s):

Seismic Behavior ◽

Lateral Displacement ◽

Bending Moment ◽

Pile Group ◽

Shaking Table ◽

Excess Pore Pressure ◽

Shaking Table Tests ◽

Pile Groups ◽

Acceleration Response ◽

Table Model

A series of shaking table model tests were performed to examine the effects of deep cement mixing (DCM) columns with different reinforcement depths on the seismic behavior of a pile group in liquefiable sand. Due to the DCM column reinforcement, the fundamental natural frequency of the model ground increases noticeably. The excess pore pressure of soils reduces with the increase of reinforcement depths of the DCM columns. Before liquefaction, the acceleration response of soils in the improved cases is obviously lower than that in the unimproved case, but the acceleration attenuation is greater after liquefaction in the unimproved case. Moreover, the lateral displacement of the superstructure, the settlement of the raft, and the bending moment of the piles in the improved cases are significantly reduced compared to those in the unimproved case, and the reduction ratios rise with the increase of reinforcement depth of the DCM columns. However, reinforcement by the DCM columns may result in the variation of the location of the maximum moment that occurs in the pile.

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