Full-scale shake table investigation of bridge abutment lateral earth pressure

Author(s):  
Patrick Wilson ◽  
Ahmed Elgamal

During strong seismic excitation, passive earth pressure at the abutments may provide resistance to longitudinal displacement of the bridge deck. The dynamic pressure component may also contribute to undesirable abutment movement or damage. Current uncertainty in the passive force-displacement relationship and in the dynamic response of abutment backfills continues to motivate large-scale experimentation. In this regard, a test series is conducted to measure static and dynamic lateral earth pressure on a 1.7 meter high bridge abutment wall. Built in a large soil container, the wall is displaced horizontally into the dense sand backfill, in order to record the passive force-displacement relationship. The wall-backfill system is also subjected to shake table excitation. In the conducted tests, lateral earth pressure on the wall remained close to the static value during the low to moderate shaking events (up to about 0.5g). At higher levels of input acceleration, a substantial portion of the backfill inertial force started to clearly act on the wall.

2011 ◽  
Vol 368-373 ◽  
pp. 461-464
Author(s):  
Ren Le Ma ◽  
Ming Yi Zhang

With the rapid development of inland wind farm in China, the costal wind farm still has not got large-scale development as the result of the higher cost of fan foundation and the more difficulty of construction. The prefabricated prestressed cylinder foundation (PPC foundation), as a new type of wind turbine foundation designed for the soft soil region such as the inter-tidal coastal zone and inland wetlands, is introduced in this paper. The condition of lateral earth pressure distribution around the foundation which determines the flexural capacity of fan foundation in the soft soil is studied. Through theoretical analysis and mathematical derivation, the result shows that the lateral earth pressure around PPC foundation is changed with depth by 1.5th power curve which has good fitting to the finite element analysis result. The simplified and improved design process is applied into the practical engineering and the good economy of PPC foundation is proved.


2018 ◽  
Vol 3 (1) ◽  
Author(s):  
Septiana Widi Astuti ◽  
Ayu Prativi

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


2021 ◽  
Vol 13 (9) ◽  
pp. 5087
Author(s):  
Hany El Naggar ◽  
Ali Iranikhah

Although some discarded tires are reused in various applications, a considerable number end up in landfills, where they pose diverse environmental problems. Waste tires that are shredded to produce tire-derived aggregates (TDA) can be reused in geotechnical engineering applications. Many studies have already been conducted to examine the behavior of pure TDA and soil-TDA mixtures. However, few studies have investigated the behavior of larger TDA particles, 20 to 75 mm in size, mixed with various types of soil at percentages ranging from 0% to 100%. In this study, TDA was mixed with gravelly, sandy, and clayey soils to determine the optimum soil-TDA mixtures for each soil type. A large-scale direct shear box (305 mm × 305 mm × 220 mm) was used, and the mixtures were examined with a series of direct shear tests at confining pressures of 50.1, 98.8, and 196.4 kPa. The test results indicated that the addition of TDA to the considered soils significantly reduces the dry unit weight, making the mixtures attractive for applications requiring lightweight fill materials. It was found that adding TDA to gravel decreases the shear resistance for all considered TDA contents. On the contrary, adding up to 10% TDA by weight to the sandy or clayey soils was found to increase the shear resistance of the mixtures. Adding up to 10% TDA by weight to the clayey soil also sharply increased the angle of internal friction from 18.8° to 32.3°. Moreover, it was also found that the addition of 25% TDA by weight to the gravelly or sandy soils can reduce the lateral earth pressure on buried structures by up to 20%. In comparison, adding 10% TDA to clay resulted in a 36% reduction in the lateral earth pressure.


Author(s):  
Xiaodong Zhao ◽  
Guoqing Zhou ◽  
Bo Wang ◽  
Wei Jiao ◽  
Jing Yu

Artificial frozen soils (AFS) have been used widely as temporary retaining walls in strata with soft and water-saturated soil deposits. After excavations, frozen soils thaw, and the lateral earth pressure penetrates through the soils subjected to freeze–thaw, and acts on man-made facilities. Therefore, it is important to investigate the lateral pressure (coefficient) responses of soils subjected to freeze–thaw to perform structure calculations and stability assessments of man-made facilities. A cubical testing apparatus was developed, and tests were performed on susceptible soils under conditions of freezing to a stable thermal gradient and then thawing with a uniform temperature (Fnonuni–Tuni). The experimental results indicated a lack of notable anisotropy for the maximum lateral preconsolidated pressures induced by the specimen’s compaction and freeze–thaw. However, the freeze–thaw led to a decrement of lateral earth pressure coefficient  K0, and  K0 decrement under the horizontal Fnonuni–Tuni was greater than that under the vertical Fnonuni–Tuni. The measured  K0 for normally consolidated and over-consolidated soil specimens exhibited anisotropic characteristics under the vertical Fnonuni–Tuni and horizontal Fnonuni–Tuni treatments. The anisotropies of  K0 under the horizontal Fnonuni–Tuni were greater than that under the vertical Fnonuni–Tuni, and the anisotropies were more noticeable in the unloading path than that in the loading path. These observations have potential significances to the economical and practical design of permanent retaining walls in soft and water-saturated soil deposits.


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