Showing papers on "Lateral earth pressure published in 2002"
TL;DR: In this article, a simple method is proposed for calculating the active and passive earth pressure coefficients in the general case of an inclined wall and a sloping backfill, based on rotational log-spiral failure mechanisms in the framework of the upper bound theorem of limit analysis.
Abstract: A simple method is proposed for calculating the active and passive earth pressure coefficients in the general case of an inclined wall and a sloping backfill. The approach used is based on rotational log-spiral failure mechanisms in the framework of the upper-bound theorem of limit analysis. It is shown that the energy balance equation of a rotational log-spiral mechanism is equivalent to the moment equilibrium equation about the centre of the log-spiral. Numerical optimisation of the active and passive earth pressure coefficients is performed automatically by a spreadsheet optimisation tool. The implementation of the proposed method is illustrated using an example. The predictions by the present method are compared with those given by other authors.
122 citations
TL;DR: In this article, a static lateral load test was performed on a full-scale 33-pile group driven in saturated low-plasticity silts and clays, and steel pipe piles were attached to a concrete pile cap creating a "fixed-head" end constraint.
Abstract: A static lateral load test was performed on a full-scale 33-pile group driven in saturated low-plasticity silts and clays. The steel pipe piles were attached to a concrete pile cap creating a "fixed-head" end constraint. A gravel backfill was compacted in place on the backside of the cap. Lateral resistance, therefore, was provided by pilesoilpile interaction, as well as base friction and passive pressure on the cap. In this case, passive resistance contributed ~40% of total resistance. The logspiral method provided the best agreement with measured resistance. Estimates of passive pressure computed by the Rankine method greatly underestimated the resistance while the Coulomb method overestimated resistance. Cap movement needed to fully mobilize passive resistance in the gravel backfill was about 6% of the cap height. This is somewhat larger than reported in other studies due likely to the underlying clay layer. P-multipliers developed for the free-head pile group gave reasonable estimates of the pilesoilpile resistance for the fixed-head pile group once gaps adjacent to the pile were considered.
108 citations
TL;DR: In this article, the authors proposed a state variable that relates the current void ratio and mean pressure of the soil to its critical state. But this variable is not suitable for modeling sand behavior within the framework of critical-state soil mechanics.
Abstract: The effort to model sand behavior within the framework of critical-state soil mechanics would benefit from a state variable that relates the current void ratio and mean pressure of the soil to its ...
108 citations
TL;DR: In this article, a large number of seismic retrofitting projects for bridges in California have revealed the need for well-documented field tests evaluating the effect of pile installation on the static and dynamic properties of soft clays.
Abstract: Numerous field and laboratory research projects have examined loading conditions, total soil stresses, and excess pore pressures during and following pile installation. Recently, a large number of seismic retrofitting projects for bridges in California have revealed the need for well-documented field tests evaluating the effect of pile installation on the static and dynamic properties of soft clays. This paper documents the geotechnical field investigation and field monitoring program, which included measurements of excess pore pressure and horizontal deformations at three radial distances from a full-scale close-ended pile driven into a deep deposit of Young Bay Mud. Significant excess pore pressures developed as a result of pile driving and they are a function of distance to the pile wall. Lateral deformations decrease with increasing distance from the pile and can be approximately described by the cylindrical cavity expansion method. iclinometer measurements show lateral deformation towards the pile wall as the excess pore pressure dissipates. These measurements are essential in the calibration and validation of analytical techniques to predict changes in properties of the foundation soil.
104 citations
TL;DR: In this article, the load in geosynthetic reinforcement layers in full-scale walls is estimated from strain measurements and converted to load through the stiffness of the reinforcement material, and the authors compared these reinforcement loads to predictions using current design practice applied to the wall case histories.
Abstract: Knowing the load in geosynthetic reinforcement layers in full-scale walls is an important step to improving internal stability design methods. Interpretation of empirical reinforcement load data enables analytical models to be properly calibrated. High-quality empirical data also provides a baseline against which new design methods can be validated. In this paper, loads in soil reinforcement layers from 16 full-scale geosynthetic wall case histories were estimated from strain measurements and converted to load through the stiffness of the reinforcement material. The paper summarizes these estimated peak loads, describes general trends in the data, and compares these reinforcement loads to predictions using current design practice applied to the wall case histories. It was found that reinforcement loads derived from strain measurements are, in general, much lower than would be predicted based on current limit equilibrium design methods that use classical earth pressure theory. The low reinforcement strains...
91 citations
TL;DR: In this article, the variation of the coefficient of earth pressure in normally consolidated and overconsolidated soil and the effect of soil compaction on the change of the horizontal effective stress are discusse
Abstract: The variation of the coefficient of earth pressure in normally consolidated and overconsolidated soil and the effect of soil compaction on the change of the horizontal effective stress are discusse...
88 citations
TL;DR: In this paper, a method of characteristics was used to generate passive earth pressure coefficients for an inclined wall retaining cohesionless backfill material in the presence of pseudostatic horizontal earthquake body forces.
Abstract: The method of characteristics was used to generate passive earth pressure coefficients for an inclined wall retaining cohesionless backfill material in the presence of pseudostatic horizontal earthquake body forces. The variation of the passive earth pressure coefficients K-pq and K-pgamma with changes in horizontal earthquake acceleration coefficient due to the components of soil unit weight and surcharge pressure, respectively, has been obtained; a closed-form solution for K-pq is also provided. The passive earth resistance has been found to decrease sharply with an increase in the magnitude of horizontal earthquake acceleration. The computed passive earth pressure coefficients were found to be the lowest when compared to all of the previous solutions available in the literature.
85 citations
TL;DR: In this article, a detailed interpretation of the evolution of stresses around a braced excavation in a deep layer of soft clay is presented, where excavation support is provided by a diaphragm wall and multiple levels of rigid cross-lot bracing.
Abstract: This paper presents a detailed interpretation of the evolution of stresses around a braced excavation in a deep layer of soft clay. Excavation support is provided by a diaphragm wall and multiple levels of rigid cross-lot bracing. Undrained shearing of the clay is represented by an advanced effective stress soil model that simulates important features of behavior including anisotropic stress-strain-strength relationships, small strain nonlinearity, and hysteretic response upon load reversal. The results provide new insight for explaining the development of lateral earth pressures for braced excavations and give a quantitative illustration of conceptual load transfer mechanisms and soil arching discussed previously in the literature. Reversals in the direction of shearing occur when the upper retained soil is squeezed against the bracing by deep-seated incremental movements in the soil mass, and arching of stresses below the lowest level of bracing. These mechanisms apply for a wide range of soil profiles when the wall is not keyed into an underlying bearing layer. Field measurements from an instrumented project in Taiwan lend credibility to the stress paths predicted in these numerical experiments.
74 citations
TL;DR: In this paper, an analytical solution for earth pressure coefficients, based on the lower bound theorem of plasticity, was proposed. But this approach is not suitable for non-planar failure surfaces.
Abstract: INTRODUCTION It is well recognised that, when wall friction is present, a non-uniform stress field arises as well as a non-planar failure surface. This renders the problem of computing exact values of earth pressures non-trivial, and analytical solutions are not available in this case. In particular, when dealing with passive earth pressure, current practice relies on solutions provided by limit equilibrium methods with a curved (typically log-spiral) surface, but as these procedures are essentially of kinematical nature they are not conservative. In fact, should the assumed mechanism be admissible in kinematics terms, these solutions represent an upper bound of the exact solution. For this reason it is of interest to search for a statically admissible stress field, because this approach provides a conservative answer or the exact one (Calladine, 1985). In this respect, the numerical solution obtained by Sokolowski (1965), based on the method of characteristics, is actually of major interest, and the one most commonly used by designers is that of Caquot & Kerisel (1948) or Kerisel & Absi (1990). This paper is intended to contribute to this problem by providing an analytical solution for earth pressure coefficients, based on the lower bound theorem of plasticity. The expression obtained for the passive earth pressure coefficient is
70 citations
TL;DR: In this paper, a practical approach for the estimation of t-z curves along bored piles by considering the nonlinear elastic properties and modulus degradation characteristics of the soil is proposed.
Abstract: The load-transfer (or t-z) curve, which reflects the interaction between a pile and the surrounding soil, is important for evaluating the load-settlement response of a pile subjected to an axial load using the load-transfer method. Preferably, the nonlinear stress-strain behavior of the soil should be incorporated into the t-z curve. This paper presents a practical approach for the estimation of t-z curves along bored piles by considering the nonlinear elastic properties and modulus degradation characteristics of the soil. A method for evaluating the modulus degradation curve from the results of a pressuremeter test is proposed. The results of load tests on one instrumented bored pile in Piedmont residual soil in Atlanta and another in the residual soil of the Jurong Formation in Singapore provide verification of the validity of the proposed approach.
67 citations
TL;DR: In this paper, the authors present experimental data of earth pressure acting against a vertical rigid wall, which moved toward a mass of dry sand, and found that the Coulomb and Terzaghi solutions calculated with the peak internal friction angle significantly overestimated the ultimate passive thrust for the retaining wall filled with dense sand.
Abstract: This paper presents experimental data of earth pressure acting against a vertical rigid wall, which moved toward a mass of dry sand. The backfill had been placed in lifts to achieve relative densities of 38, 63, and 80%. The instrumented retaining-wall facility at National Chiao Tung University in Taiwan was used to investigate the effects of soil density on the development of earth pressure. Based on the experimental data, it has been found that the Coulomb and Terzaghi solutions calculated with the peak internal friction angle significantly overestimated the ultimate passive thrust for the retaining wall filled with dense sand. As the wall movementS exceeded 12% of the wall height H, the passive earth thrust would reach a constant value, regardless of the initial density of backfill. Under such a large wall movement, soils along the rupture surface had reached the critical state, and the shearing strength on the surface could be properly represented with the residual internal-friction angle. The ultimate passive earth pressure was successfully estimated by adopting the critical state concept to either Terzaghi or Coulomb theory. CE Database keywords: Passive pressure; Earth pressure; Sand; Vertical angles.
Book•
03 Jan 2002TL;DR: In this paper, the authors proposed a solution of the one dimensional consolidation differential equation to solve the problem of stability problems in soil mechanics, and applied it to the stability problems of cliff walls and retaining walls.
Abstract: 1. Nature of Soils, Plasticity and Compaction 1.1 Introduction 1.2 Nature and chemistry of soils 1.3 Mass-volume relationships 1.4 Particle size distribution 1.5 Index properties and volume change in fine grained soils 1.6 Soil classification for geotechnical purposes 1.7 Compaction 1.8 Problems 1.9 References 2. Effective Stress and Pore Pressure in Saturated Soils 2.1 Introduction 2.2 State of stress at a point due to self-weight 2.3 State of stress at a point due to external forces 2.4 Problems 2.5 References 3. The Movement of Water through Soil 3.1 Introduction 3.2 Principles of flow in porous media 3.3 Permeability 3.4 Flow nets 3.5 Mathematics of the flow in soil 3.6 Seepage through earth dams 3.7 Problems 3.8 References 4. Shear Strength of Soils and Failure Criteria 4.1 Introduction 4.2 Mohr-Coulomb failure criterion 4.3 Laboratory shear strength tests 4.4 Stress-strain behaviour of sands and clays 4.5 Critical state theory 4.6 Problems 4.7 References 5. Stress Distribution and Settlement in Soils 5.1 Introduction 5.2 Fundamental equations of elasticity 5.3 Stress distribution due to external and internal loading 5.4 Elastic settlement of footings 5.5 Soil-footing interaction models 5.6 Problems 5.7 References 6. One Dimensional Consolidation 6.1 Introduction 6.2 Consolidation indices and settlement prediction 6.3 Solution of one dimensional consolidation differential equation 6.4 Application of parabolic isochrones 6.5 Limitations of one dimensional consolidation theory 6.6 Problems 6.7 References 7. Application of Limit Analysis to Stability Problems in Soil Mechanics 7.1 Introduction 7.2 Lower bound solution 7.3 Upper bound solution 7.4 Finite element formulation of the bound theorems 7.5 Limit equilibrium method and concluding remarks 7.6 Problems 7.7 References 8. Lateral Earth Pressure and Retaining Walls 8.1 Introduction 8.2 Earth pressure at-rest 8.3 Rankine's theory for active and passive soil pressures 8.4 Coulomb wedge analysis 8.5 Common types of retaining structures and factor of safety 8.6 Static analysis of cantilever and gravity retaining walls 8.7 Static analysis of sheet pile walls 8.8 Internally stabilized earth retaining wall 8.9 The overall stability of retaining structures 8.10 Problems 8.11 References 9. Stability of Earth Slopes 9.1 Introduction 9.2 Stability of slopes in cu, phiu = 0 Soil-circular failure surface 9.3 Stability of slopes in c', phi' Soil - The method of slices 9.4 Stability of infinitely long earth slopes 9.5 Stability of reinforced and nailed earth slopes 9.6 General slope stability analysis 9.7 Application of the wedge method to unreinforced slopes 9.8 Concluding remarks 9.9 Problems 9.10 References 10. Bearing Capacity of Shallow Foundations and Piles 10.1 Introduction 10.2 Ultimate bearing capacity of shallow foundations 10.3 Field tests 10.4 Axial ultimate bearing capacity of piles 10.5 Pile groups 10.6 Problems 10.7 References
TL;DR: A series of laboratory model tests in soft clay was conducted to investigate the behavior of coupled piles subjected to lateral soil movements (passive) and to determine the ultimate soil pressure acting on the pile shaft.
Abstract: A series of laboratory model tests in soft clay was conducted to investigate the behavior of coupled piles subjected to lateral soil movements (“passive” piles), and to determine the ultimate soil pressure acting on the pile shaft. Two piles in a row (center-to-center “joining” line being perpendicular to the direction of the applied soil movements) and in a line (center-to-center “joining” line being in the direction of the applied soil movements) were considered. The ultimate soil pressures along the pile shaft for two piles in a row and in a line with pile spacings of three and five times the pile width (B=20 mm) were lower than those for single passive piles. Group effects still existed even with a pile spacing of 5 B for coupled piles in a row and in a line. Group factors decrease as pile spacing decreases for piles in a row. The test results also indicated that different distributions of limiting soil pressures along the pile shaft were developed for the single and coupled passive piles.
TL;DR: In the presence of pseudo-static seismic forces, passive earth pressure coefficients behind retaining walls were generated using the limit equilibrium method of analysis for the negative wall frict... as mentioned in this paper...
Abstract: In the presence of pseudo-static seismic forces, passive earth pressure coefficients behind retaining walls were generated using the limit equilibrium method of analysis for the negative wall frict...
TL;DR: In this article, the von Mises constitutive model was employed to model the non-linear stress-strain soil behavior and to determine the ultimate soil pressures acting along the pile shaft.
Abstract: Three-dimensional finite element analysis was carried out to investigate the behaviour of single piles subjected to lateral soil movements and to determine the ultimate soil pressures acting along the pile shaft. The finite element analysis program ABAQUS was used for the analysis and run on a SUN Workstation. The von Mises constitutive model was employed to model the non-linear stress–strain soil behaviour. The pile was assumed to have linear elastic behaviour. This was considered to be a reasonable approximation, as the maximum stress developed in the pile did not exceed the yield stress of the concrete pile. The length of the pile is 15 m, the width of the square pile is 1 m. The three-dimensional finite element mesh used in the analysis was optimized taking into account the computing capacity limitations of the Sun Workstation. The computed ultimate soil pressures agreed well with those from the literature. The shapes of the soil pressure versus soil movement curves and the soil pressure versus the relative soil–pile displacement curves as well as the magnitude of the relative soil–pile displacement to mobilize the ultimate soil pressures were in reasonable agreement with those reported by other researchers. Copyright © 2002 John Wiley & Sons, Ltd.
01 Feb 2002
TL;DR: In this paper, a database is presented of case histories showing long-term set-up of driven piles in non-cohesive soil, revealing that longterm setup can be substantial.
Abstract: A database is presented of case histories showing long-term set-up of driven piles in non-cohesive soil, revealing that long-term set-up can be substantial — an average of 40% per log cycle of time being observed. The main results from a comprehensive study of the mechanisms behind pile set-up are presented. In the main, the study is based on pile loading tests, undertaken at different points in time, on piles instrumented with earth pressure cells on the shaft. In addition, dynamic testing and torque testing on small-scale rods were also performed at different points in time. It was concluded that pile set-up is caused by two strongly interconnected mechanisms: creep (stress relaxation) and soil aging (increasing dilation and stiffness). A conceptual model explaining the underlying process is presented.
TL;DR: In the conventional design of retaining walls and bridge abutments, the lateral earth pressure due to live load surcharge is estimated by replacing the actual highway loads with a 600 mm layer of backfill as mentioned in this paper.
Abstract: In the conventional design of retaining walls and bridge abutments, the lateral earth pressure due to live load surcharge is estimated by replacing the actual highway loads with a 600 mm layer of backfill. This original recommendation was made several decades ago when the highway truck loads were much lighter. A number of researchers have shown that the pressure exerted on the wall due to live load surcharge is greater near the surface and is diminished nonlinearly throughout the height of the wall. The heavier highway loads and the demonstrated nonlinear earth pressure distribution require a need for a more rational method for obtaining the equivalent height of backfill. This paper discusses theoretical background, an analytical approach to estimation of actual earth pressure, a number of innovative approaches to obtain a simplified pressure distribution, an extensive parametric study, calibration procedures for the traditional method, and recommendations.
TL;DR: In this paper, a modified upward infiltration method (UIM) was proposed for determining soil hydraulic properties in the wetting direction, using a Mariotte system to impose a constant head boundary condition on the bottom of a soil column, allowing water to be taken up by the soil material under negative pressure head.
Abstract: This note describes a modified upward infiltration method (UIM), which combines laboratory experiments and inverse parameter estimation for determining soil hydraulic properties in the wetting direction. The laboratory method used a Mariotte system to impose a constant head boundary condition on the bottom of a soil column, allowing water to be taken up by the soil material under negative pressure head. Tensiometers installed along the column measured the change in soil pressure head before and after wetting front arrival. The HYDRUS-1D code was used to obtain an optimal set of van Genuchten parameters, using pressure head and cumulative flux data as auxiliary variables in the objective function. Two soil types (a fine sand and a sandy loam) were tested in triplicate in uniformly-packed soil columns. The results of the uniform column experiments were repeatable, and showed excellent fits between observed and predicted data. Fitted parameters were used in forward simulations to independently predict water flow behavior in layered columns of the same soil material. The forward simulations successfully predicted water flow for sand-over-loam and loam-over-sand combinations in layered columns. The relative simplicity of the experimental procedure and the availability of appropriate numerical models renders the modified upward infiltration method an alternative for determining wetting hydraulic properties of soils.
TL;DR: In this article, the authors performed tunneling model tests in an unconsolidated ground with inclined artificial layers, where aluminum rods and aluminum blocks were used to simulate the model ground.
01 May 2002
TL;DR: In this paper, the structural performance of thermoplastic pipes under relatively deep soil cover conditions was evaluated using a series of sensors and measurements of the diameter of the thermoplastics.
Abstract: This report provides information regarding the structural performance of thermoplastic pipes under relatively deep soil cover conditions. The eighteen (12 HDPE, 6 PVC) thermoplastic pipes, with diameter ranging from 30 to 60 in., were instrumented with sensors, embedded in granular backfill in shallow trenches, and subjected to 20-ft. or 40-ft. high soil fill for about 10 months. Their installation plans involved two types of backfill soil, three relative compactions, and varying bedding thickness to study the effects of these installation parameters on the pipe performance.
TL;DR: In this article, an analysis of seismic passive/active thrust on a retaining wall is proposed, in which Kotter's equation is used to obtain the distribution of soil reaction on the failure plane.
TL;DR: In this paper, the use of a compressible layer such as expanded polystyrene blocks behind a rigid retaining wall and geogrid layers embedded in a dense granular backfill is examined as a reinforcement technique for retaining wall structures.
TL;DR: In this paper, the structural performance of large-diameter, profile-wall thermoplastic pipes under deep soil cover was evaluated using field-monitored structural performance data accumulated over about 2 years, which indicated that these HDPE pipes are performing satisfactorily.
Abstract: Although the study of pipe-soil interaction has more than 80 years of history, a lack of long-term field performance data still exists when it comes to the structural performance of large-diameter, profile-wall thermoplastic pipes under deep soil cover. Field-monitored structural performance data were taken for 1050-mm (42-in.) diameter, corrugated high-density polyethylene (HDPE) pipes, which were subjected to 6.1-m (20-ft) and 12.2-m (40-ft) soil fill heights at the ORITE deep burial test site at the Ohio Research Institute for Transportation and the Environment. The field data accumulated over about 2 years indicate that these HDPE pipes are performing satisfactorily. None of the pipes deflected more than -2.5% vertically and 1% horizontally. Closer examinations of the field data obtained at the end of construction and a few months afterward provided insights into the HDPE pipe performance under deep soil cover. Among the analytical methods evaluated in light of the field data, the elastic solutions established by Burns and Richard were most promising in predicting the field performance of the HDPE pipes under deep soil fill.
TL;DR: In this article, an elasto-plastic joint constitutive law is proposed to model the shearing behavior of joints in load bearing masonry walls, where the joints were sheared using a shear box test.
Abstract: Wind, earth pressure, and earthquakes acting on a building generate bending effects and produce shear stresses in load bearing masonry walls. Stress and strain responses during shearing of masonry joints indicate unrecoverable shear and normal deformation that demand use of a constitutive model specifically developed for joints. In this study, an elasto-plastic joint constitutive law is proposed to model the shearing behavior of joints in load-bearing masonry walls. The brick-mortar bed joints were sheared using a shear box test. The physical parameters of the model were obtained from the experimental data. The load-displacement response observed experimentally was analyzed using the proposed constitutive law. The model appears to predict the shearing behavior of brick-mortar bed joints reasonably well. The study presented herein provides a basis for using an analytical method for determining shearing displacement response of brick-mortar bed joints by applying an elasto-plastic constitutive law for joints and determining its parameters from the shear testing of brick-mortar bed joints.
TL;DR: In this paper, a 3D finite element analysis representing a typical construction sequence for a diaphragm-type retaining wall is compared with a corresponding plane strain analysis and field data from the A4/A46 Batheaston-Swainswick bypass.
Abstract: Although long retaining walls are usually analysed in the permanent condition by means of a plane strain analysis, three-dimensional effects may be significant in limiting ground movements at certain stages during construction. This is particularly true for embedded diaphragm-type retaining walls propped at formation level. In this paper, a three-dimensional finite element analysis representing a typical construction sequence for such a wall is compared with a corresponding plane strain analysis and field data from the A4/A46 Batheaston–Swainswick bypass. The results are used to assess the significance of three-dimensional effects during construction, and suggest how these can be utilised to minimise ground movements.
Journal Article•
TL;DR: In this article, the authors performed model tests for passive earth pressure acting against a vertical rigid wall, which moved into a mass of dry sand under various modes of wall movements, including translation, rotation and rotation.
Abstract: In this paper,In order to improve the understanding of the factors governing the magnitudes and distributions of the earth pressures on rigid retaining wall,model tests were performed for passive earth pressure acting against a vertical rigid wall, which moved into a mass of dry sand under various modes of wall movements. The types of wall movement includes translation(T),rotation about a point above the wall top(RTT) and rotation about a point below the wall base(RBT).
23 Oct 2002
TL;DR: In this article, a model pipe with a diameter of 260 mm and a plate with bi-axial load cells was used for pit tests to investigate the relationship between pipe intrusion resistance and the interface of the pipe and ground.
Abstract: The behavior of a buried pipeline is significantly influenced by its interaction with the surrounding ground as well as the backfill material. The thrust force generated by the action of internal water pressure tends to move the bend of underground pipeline to the back side. This thrust force is supported by the passive soil pressure that affects the back ground. The concrete block is also used at the bend to minimize the thrust. There is a lack of study on the magnitude of passive soil pressure and distribution of a pipe bend. Such information are required for design. In the current design standard for irrigation pipeline in Japan, back passive soil pressure is assumed to increase in depth with a trapezoid distribution. In other words, when the bend is buried without the thrust block, a trapezoidal passive earth pressure is assumed by projecting it laterally. However, the earth pressure distribution is not readily known when the pipe moves laterally in the ground. In addition, it is not clear about the relationship between pipe intrusion resistance and the interface of the pipe and ground. In this paper, pit tests were conducted using a model pipe having a diameter of 260 mm that was equipped with 20 bi-axial load cells. In addition, similar tests were conducted using a plate with bi-axial load cells. As the pipe moved horizontally in the ground, the distribution of the back earth pressure acting on the bend and plate, and development of slip surface in the backfill sand were measured and investigated.
01 Nov 2002
TL;DR: In this article, the development of lateral passive pressures during the failure of masonry arch bridges was investigated using 1/12th scale models of a 6 m, single-span, three-ring, brickwork arch.
Abstract: This paper considers the development of lateral passive pressures during the failure of masonry arch bridges. It has been known for some time that the sway failure mechanism of these bridges develops significant stabilising soil pressures but quantitative figures for use in bridge assessment remain largely unknown, particularly for deep arches. This paper considers the pressures developed for two geometries typical of the range of structures found in the UK, one of span/rise = 4 and the other semicircular. The experiments were performed in a geotechnical centrifuge using 1/12th scale models of a 6 m, single-span, three-ring, brickwork arch. The results confirm earlier work suggesting that full passive pressure limits are not reached; however, it is clear that for the soil type tested limiting soil pressures at all monitored locations were achieved. A passive pressure profile is postulated for arch bridge assessment and application of the profile to the assessment of the two bridges tested is undertaken.
Patent•
10 May 2002
TL;DR: In this paper, the problem of constructing a retaining wall in a small and rigid shape at its side of reinforcing a wall face by allotting soil pressure on a bank to two types of retaining walls is addressed.
Abstract: PROBLEM TO BE SOLVED: To construct a retaining wall in a small and rigid shape at its side of reinforcing a wall face by allotting soil pressure on a bank to two types of retaining walls SOLUTION: Blocks 6 are stacked on a precast concrete base 5 to construct a block stack retaining wall 1 in a vertically sectional inverted T-shape which reinforces the wall face of the bank B A reinforced concrete connection column 14 is formed in a bottom-larger shape inside hollow columns 9 for the blocks 6, the upper and lower blocks 6 are connected to each other via the connection column 14, and the lower end of the connection column 14 is joined to the base 5 A plurality of planar reinforcing members 19 in the state of being cut off the blocks 6 are embedded in the bank B and upper and lower soil layers are connected to each other via the planar reinforcing members 19 to construct a tapered reinforced soil retaining wall 2 which makes the bank B self-supported A buffer soil retaining wall 3 is laid between the block stack retaining wall 1 and the reinforced soil retaining wall 2 so that the block stack retaining wall 1 bears part of the soil pressure on the retaining wall 3 COPYRIGHT: (C)2004,JPO
Journal Article•
TL;DR: Based on track vibrating acceleration data measured from tunnels of Shanghai Metro Project, the numerical simulations by using 3D and 2D FEM are carried out in order to understand the dynamic response of overlap tunnels in close proximity to Nanpu Bridge Project due to the train抯 vibrating load as discussed by the authors.
Abstract: Based on track vibrating acceleration data measured from tunnels of Shanghai Metro Project, the numerical simulations by using 3D and 2D FEM are carried out in order to understand the dynamic response of overlap tunnels in close proximity to Nanpu Bridge Project due to the train抯 vibrating load. The follwing conclusions are given: 1.mutual influences between the overlap tunnels are much greater than the parallel ones; 2. the longer the distance between the tunnels, the less the mutual influences; 3. for the tunnel structure design, the static soil pressure is the key load, and the additional stress induced by the train抯 vibrating load is much smaller than the stress induced by the static load.