The earth pressure behind full-height frame integral abutments supporting granular fill

2007 ◽  
Vol 44 (3) ◽  
pp. 284-298 ◽  
Author(s):  
Ming Xu ◽  
Chris RI Clayton ◽  
Alan G Bloodworth
Keyword(s):  
Particle Shape ◽  
Radial Strain ◽  
Earth Pressure ◽  
Length Change ◽  
Coarse Sand ◽  
Lateral Earth Pressure ◽  
The Earth ◽  
Granular Particle ◽  
Integral Abutments ◽  
Full Height

Compared with conventional bridges, integral bridges have no bearings or joints between the deck and abutments and thus can significantly reduce maintenance requirements and costs over the bridge's lifetime. However, there is uncertainty about the ultimate magnitude of the lateral earth pressure behind such abutments, as they are forced to move with the deck length change caused, for example, by daily and annual variations in the effective bridge temperature. This research investigated the earth pressure that would be expected to occur behind full-height frame integral abutments backfilled by granular materials. Radial strain-controlled cyclic stress path testing has been conducted on coarse sand specimens and a glass ballotini specimen. The results suggest that for integral abutments retaining uniform coarse sand, the lateral earth pressure will experience systematic increases for almost all cyclic strain levels, eventually reaching states of stress close to both active and passive. The mechanism of the buildup of lateral stress is explored, and it appears to be associated with nonspherical granular particle shape. The implications for frame integral abutment design are discussed.Key words: integral abutments, granular, particle shape, earth pressure, stiffness.

The earth pressure behind full-height integral abutments

2005 ◽  
Vol 90 (6) ◽  
pp. 55-58 ◽  
Author(s):  
Ming Xu ◽  
Alan G. Bloodworth
Keyword(s):  
Earth Pressure ◽  
The Earth ◽  
Integral Abutments ◽  
Full Height

scholarly journals Lateral Earth Pressure behind Walls Rotating about Base considering Arching Effects

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Dong Li ◽  
Wei Wang ◽  
Qichang Zhang
Keyword(s):  
Conversion Factor ◽  
Retaining Wall ◽  
Earth Pressure ◽  
Soil Mass ◽  
Shear Stresses ◽  
Key Factors ◽  
Lateral Earth Pressure ◽  
The Earth ◽  
Common Effect ◽  
The Common

In field, the earth pressure on a retaining wall is the common effect of kinds of factors. To figure out how key factors act, it has taken into account the arching effects together with the contribution from the mode of displacement of a wall to calculate earth pressure in the proposed method. Based on Mohr circle, a conversion factor is introduced to determine the shear stresses between artificial slices in soil mass. In the light of this basis, a modified differential slices solution is presented for calculation of active earth pressure on a retaining wall. Comparisons show that the result of proposed method is identical to observations from model tests in prediction of lateral pressures for walls rotating about the base.

Model for predicting displacement-dependent lateral earth pressure

2009 ◽  
Vol 46 (8) ◽  
pp. 969-975 ◽  
Author(s):  
Guoxiong Mei ◽  
Qiming Chen ◽  
Linhui Song
Keyword(s):  
Earth Pressure ◽  
The State ◽  
Passive State ◽  
Test Results ◽  
Lateral Earth Pressure ◽  
The Earth ◽  
Proposed Model ◽  
Pressure Changes ◽  
The Relationship ◽  
Good Agreement

A model for predicting displacement-dependent lateral earth pressure was proposed based on an earth pressure – displacement relationship commonly observed in practice. The proposed model is a monotonically increasing and bounded function, with an inflection point at the displacement of s = 0 at which the earth pressure changes from the intermediate active state (the state between active and at-rest) to the intermediate passive state (the state between at-rest and passive). The proposed model can predict the relationship between earth pressure and retaining structure movement for any condition intermediate to the active and passive states, which was verified by the experimental data reported in published literature. The predicted lateral earth pressure coefficients are in good agreement with the test results of model tests reported in the literature.

Determination of apparent earth pressure diagram for anchored walls in c–φ soil with surcharge

2020 ◽  
Vol 17 (4) ◽  
pp. 481-489
Author(s):  
Seyyed Pouya Alavinezhad ◽  
Hadi Shahir
Keyword(s):  
Retaining Wall ◽  
Ground Surface ◽  
Earth Pressure ◽  
Ground Level ◽  
Content Type ◽  
Lateral Earth Pressure ◽  
The Earth ◽  
Real Distribution ◽  
Strain Modeling

Purpose The purpose of this study is to present a diagram for the lateral earth pressure of c–φ soils exerted on anchored walls in presence of surcharge. Design/methodology/approach To this end, two-dimensional plane strain modeling of anchored wall was carried out in Plaxis software. To validate the numerical model, two excavations with different specifications were simulated and the model results were compared with the available results. Subsequently, a parametric analysis was done and based on its results, a diagram was proposed for the lateral earth pressure of c–φ soils including the surcharge effects. Findings The proposed diagram without the surcharge and cohesion effects is a trapezoidal with zero value at the ground surface that is linearly approaching the apparent earth pressure of sand according to Terzaghi and Peck (1967) at 0.1H (H: wall height). The surcharge and cohesion effects at the ground level is 4 Ka*q and 0, respectively, and below 0.1H, they are treated as the same way for lateral earth pressure of a retaining wall. It should be emphasized that the apparent pressure diagram for design does not resemble the real distribution of earth pressure against the wall and it is for calculating the values of the anchors loads. Originality/value The available diagrams to determine the earth pressure exerted on the anchored walls are related to sandy or clayey soils and do not take the presence of surcharge into account. Thus, the proposed diagram is quite original and different from the previous ones.

The Launching Technique for Shield-Driven Tunnel with an Under-Pressure Soil-Chamber in Soft Layers

2011 ◽  
Vol 243-249 ◽  
pp. 953-958
Author(s):  
Bo Yan ◽  
Guo Long Yang ◽  
Hui Lin ◽  
Chang Xue Shi
Keyword(s):  
Earth Pressure ◽  
Coarse Sand ◽  
Filling Material ◽  
Active Earth Pressure ◽  
Main Principle ◽  
Soft Layer ◽  
Safety Coefficient ◽  
The Earth ◽  
Pressure Equilibrium ◽  
Engineering Practices

In order to improving the launching technique in soft layer, the paper proposed the soil-chamber under pressure on the launching technique basing on engineering practices. The main principle is: using the earth pressure equilibrium, grouting the filling material when the Shield launching, establishing the active earth pressure ahead of time, which makes in advance the action pressure supports to the coarse sand cross section, that prevents from the water and soil spouting effectively. Because the active earth pressure, enhance the initial sending safety coefficient, and shorten the reinforcement length of the initial launching, and decrease the initial launching cost.

New Method for Measurement of Lateral Earth Pressure in Cohesive Soils

1975 ◽  
Vol 12 (1) ◽  
pp. 142-146 ◽  
Author(s):  
K. Rainer Massarsch
Keyword(s):  
Pore Pressure ◽  
Effective Stress ◽  
Basic Concept ◽  
Earth Pressure ◽  
New Method ◽  
Cohesive Soils ◽  
Pressure Measurements ◽  
Lateral Stress ◽  
Lateral Earth Pressure ◽  
The Earth

A new method is described by which the total lateral stress in cohesive soils can be measured. When used in combination with pore pressure measurements, the lateral effective stress, the stress change, and the coefficient of lateral earth pressure at rest, K0, can be calculated. The basic concept of the earth pressure cell and its installation, as described in this report, are simple.

Behaviors of Drained Lateral Extension for Saturated Sand and Their Applications

2007 ◽  
Vol 23 (1) ◽  
pp. 51-62
Author(s):  
C.-P. Yang
Keyword(s):  
Numerical Solutions ◽  
Retaining Wall ◽  
Radial Strain ◽  
Prediction Method ◽  
Earth Pressure ◽  
Active State ◽  
Lateral Extension ◽  
Confining Stress ◽  
Wall Movement ◽  
The Earth

AbstractPractically all retaining walls may rotate, yet movements of the wall could be restricted, particularly under working conditions. Since the earth pressure on the retaining wall often deviates from the fully active state, there is a need for predicting the earth pressure at any wall movement. The shearing behavior of backfill behind the wall plays an essential role for predicting the redistributions of earth pressure for different wall movements. This paper studies 25 sets of test for analyzing the drained lateral extension behaviors of saturated Ottawa sand. Three methods are used to interpret the active state of specimens and it is found that the monotonic increasing property of the σ'cs – εrp plot obtained by using the (q')max method is more obvious than those obtained by the other two methods. Where σ'cs is an initial confining stress of specimen for lateral extension test, and εrp is a radial strain of specimen developed at the active state. The specimens, with the relative density between 15% ∼ 90% and with the confining stress between 80kPa ∼ 280kPa, range their values of εrp from −1.18% to −2.99%. The magnitude of εrp can be used to judge the secure level of deformation for a retaining structure. Subsequently, this study derives a formula to predict the redistribution of earth pressure on a retaining wall when the wall moving outwards based on the results of those lateral extension tests. This prediction method is a new approach to study the problems of earth pressure. Comparisons of predicted results from numerical solutions technique and observations from model tests show that the performance of this method is reasonable.

Coordinated optimization control of shield machine based on dynamic fuzzy neural network direct inverse control

2020 ◽  
pp. 014233122098027
Author(s):  
Xuanyu Liu ◽  
Wentao Wang ◽  
Yudong Wang ◽  
Cheng Shao ◽  
Qiumei Cong
Keyword(s):  
Fuzzy Neural Network ◽  
Control Method ◽  
Earth Pressure ◽  
Screw Conveyor ◽  
Inverse Control ◽  
The Earth ◽  
Coordinated Optimization ◽  
Optimization Control ◽  
Fuzzy Neural ◽  
Shield Machine

During shield machine tunneling, the earth pressure in the sealed cabin must be kept balanced to ensure construction safety. As there is a strong nonlinear coupling relationship among the tunneling parameters, it is difficult to control the balance between the amount of soil entered and the amount discharged in the sealed cabin. So, the control effect of excavation face stability is poor. For this purpose, a coordinated optimization control method of shield machine based on dynamic fuzzy neural network (D-FNN) direct inverse control is proposed. The cutter head torque, advance speed, thrust, screw conveyor speed and earth pressure difference in the sealed cabin are selected as inputs, and the D-FNN control model of the control parameters is established, whose output are screw conveyor speed and advance speed at the next moment. The error reduction rate method is introduced to trim and identify the network structure to optimize the control model. On this basis, an optimal control system for earth pressure balance (EPB) of shield machine is established based on the direct inverse control method. The simulation results show that the method can optimize the control parameters coordinately according to the changes of the construction environment, effectively reduce the earth pressure fluctuations during shield tunneling, and can better control the stability of the excavation surface.

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