Lateral Soil Pressure Research Articles

Coefficient of lateral soil pressure when using reinforced and unreinforced piles filled sand & granite grain for strengthening roads layers

Coefficient of lateral soil pressure when using reinforced and unreinforced piles filled sand & granite grain for strengthening roads layers

Response of group piles subjected to coupled vertical-eccentric lateral-seismic loads

In seismic prone regions, analyzing loaded pile groups can be challenging because of limitations in conventional design methods and the inability of small-scale laboratory tests to accurately replicate the real behavior. Studying how pile group response is affected by the combined impact of vertical, concentric, and seismic loads is challenging. One of the limitations pertains to the intricacy of scaling up experiments, particularly in creating large-scale laboratory models. Thus, a numerical analysis may be appropriate for capturing the response. This study aimed to understand the pile group response in dense sand subjected to vertical, eccentric lateral, and seismic loadings via a large-scale 3D nonlinear finite element model. The validation results indicate that the numerical approach accurately predicts the behavior of pile groups in dense sand. Then, two different layouts of pile groups are analyzed under various loading scenarios on the basis of the recorded data from the El Centro earthquake. The results revealed that the number and arrangement of piles significantly affect the induced settlement. Compared with the 5-pile groups, the 3-pile groups presented higher maximum bending moments under vertical loading. However, the response of the 5-pile groups varied, as they experienced higher bending moment values without vertical loading. The peak lateral soil pressures were higher in the 3-pile groups. Some significant variations appeared in the induced torque resistances when the 5-pile groups were compared with the 3-pile groups. This study demonstrated the reliability of the used numerical approach for analyzing the response of pile groups in dense sand, as an alternative to laboratory test models.

Numerical modeling of seismic performance of shallow steel tunnel

Advanced numerical models can be used to complement experimental results and further elucidate their findings. This is particularly true when certain scaled model “adjustments” are incorporated in the testing scheme to reduce the testing cost or schedule. This study conducts comprehensive finite element modeling to simulate large-scale shaking table tests conducted by Kim et al. (2023) [1] to evaluate the seismic performance of steel tunnels. The numerical model was calibrated by comparing its predictions with the experimental observations in the initial tests. The calibrated model was then validated by comparing its predictions with the results obtained from other test models and subjected to different input ground motions. The validated model was employed to comprehensively investigate the effects of the testing scheme parameters including the input motion time scaling, tunnel burial depth, and soil relative density. It was found that reducing the time scale factor during the tests led to decreased seismic responses. It was also found that the presence of overburden soil on top of the tunnel resulted in higher seismic bending moment values, and that higher overburden height increased both lateral and vertical soil pressures on the tunnel side walls and top slab. In addition, lateral soil distortion and tunnel deformations were found to be directly correlated with the overburden soil height. Furthermore, in the absence of overburden soil, there was a significant amplification in horizontal soil acceleration. The results demonstrated that lower-density sand bed experienced greater acceleration amplification and larger displacement, and the tunnel experienced larger lateral soil pressure and higher racking. Additionally, the results revealed that subjecting the same soil bed to several shaking tests affected its stiffness, and hence affected the test observations in the subsequent tests. This should be considered when planning shaking table tests. Finally, the strain values and racking ratios obtained from the numerical simulations and the shaking tests were in agreement with the values obtained from the FHWA procedure.

The 3d response of a large-scale masonry arch bridge - part I: Performance under low and medium loading levels

Masonry arch bridges are characterised by three-dimensional (3D) behaviour when subjected to external eccentric loading (e.g., vehicle loads). The arch ring, abutments, backfill and spandrel walls may interact with each other in a complex manner, leading to a 3D mode of response that can have a significant impact on the initiation and propagation of damage. However, there is a dearth of experimental data from tests designed to investigate the 3D behaviour of masonry arch bridges, particularly under loading levels below those required to cause failure. This paper presents results from tests on a large-scale brickwork masonry arch bridge subjected to low- and mid-level static loads under laboratory conditions. Point loads of increasing magnitude were applied at different locations on the top of the backfill in order to investigate 3D response and damage accumulation. Details of the experimental setup, material characterisation, and the results obtained from static and repeated load tests at low- and mid-level load magnitudes are presented herein. Results demonstrate that the bridge exhibited a 3D mode of response under eccentric point loads. Loading at the mid-span resulted in greater deformation of the arch barrel compared to loading at the quarter- and three-quarter-span points, due to the shallower backfill depth over the crown. Under the mid-level loading, stiffness degradation was observed during the testing regime, suggesting an accumulation of damage in the bridge. Moreover, when loading was applied close to a spandrel wall, measurable out-of-plane deformation of the spandrel wall was observed, with this deformation increasing significantly as the load was increased from 150 kN to 250 kN. This results from a combination of increased lateral soil pressure and decreased shear resistance at the arch-spandrel wall interface.

Implementation of Mini Piles and Retaining Wall in the Construction of the North Kalimantan Provincial DPRD Building in Bulungan Regency

Piles are used as the foundation for a building's construction when the underlying soil beneath the structure lacks sufficient bearing capacity to support the weight of the construction and its load, or when hard soil with enough bearing capacity lies at a significant depth. Retaining walls are a type of civil construction built to withstand the lateral active pressure of soil or water. Therefore, the construction of a retaining wall must be planned and designed to safely counter potential forces that could cause structural failure. The purpose of this writing is to understand the implementation of mini pile foundations and retaining walls concerning the stability control of the retaining wall against sliding, overturning, and soil-bearing capacity. The observational method used involves collecting secondary and primary data. The mini pile foundations are driven to a specified depth, with each pile segment being 4.0 meters long, and this piling activity aligns with the plan. The retaining wall used is a cantilever retaining wall with concrete quality K-300 f’c 25 MPa, where the successive heights, upper width, and bottom width of the retaining wall are 4.5 m, 0.3 m, and 2.7 m, respectively.

Research on Engineering Characteristics of Cement Mixing Piles Strengthening Steel Sheet Pile Structure Wharf

In order to solve the technical problem of using steel sheet piles in soft soil foundations of deep water docks, the use of grid type cement mixing pile walls to reinforce the in-situ soft soil behind steel sheet pile docks is a new type of composite structure attempt. This paper combines practical engineering and uses finite element analysis software to study the vertical displacement, vertical stress, and horizontal displacement changes of reinforced soil in three layout forms: non-mixing pile structure, grid type cement mixing structure, and dispersed mixing pile structure. The results show that the grid type cement mixing pile structure can reduce soil settlement, improve the stability of reinforced soil, and reduce lateral soil pressure on steel sheet piles compared to the non-mixing pile structure and the dispersed mixing pile structure. In the practical application of steel sheet pile wharf engineering, the use of grid type cement mixing piles can improve the stability and engineering benefits of the wharf structure.

Seismic response of retaining walls: Theoretical parametric insights after centrifuge validation

To gain insight into the dynamics of retaining systems, the seismic response of a “non-displacing” U-shaped and a “displacing” cantilever retaining wall in dry sand stratum is studied by numerical analyses using a refined constitutive model, with the wall–soil interface allowing separation and sliding. The results were motivated from, and are successfully compared with, a series of comprehensive centrifuge experiments by Sitar and co-workers. Tests and analyses use as base excitation three accelerograms from Kobe, Kocaeli and Loma Prieta. Results are presented in terms of acceleration time-histories, response spectra, plastic strain contours, and lateral soil pressures. Emphasis is given to numerically–obtained soil lateral pressures, and the parametric study shows that while such pressures are difficult to accurately predict, they may nevertheless be in (barely satisfactory) agreement in shape and even often in magnitude with either: (i) Mononobe–Okabe–type, or (ii) the Veletsos and Younan (1994) [39] analytical solutions, depending on the displacement constraints of the wall, the rotational flexibility at the base, and the severity of the excitation.

Additional Lateral Soil Pressure Due to Vehicle (at Constant Speed): The Distribution and Comparison to Its Static Load

Additional Lateral Soil Pressure Due to Vehicle (at Constant Speed): The Distribution and Comparison to Its Static Load

Field study on installation effects of pre-bored grouted planted pile in deep clayey soil

This paper presents the results of field tests performed to investigate the installation effects of pre-bored grouted planted (PGP) pile in deep clayey soil. The variation of horizontal soil displacements, excess pore water pressures and lateral soil pressures was measured in the PGP pile installation process. The test results show that the drilling and grouting process induced large horizontal soil displacements in the soil within a radial distance of 2 d ( d is pile diameter), and the maximum horizontal soil displacements induced by the drilling and grouting process were smaller than 15.9 mm when the radial distance reached 4–5 d. Moreover, the horizontal soil displacements decreased along the soil layer depth, as the superficial soil layers were of small deformation modulus and lateral soil pressure. The drilling process brought large excess pore water pressures in the soil when the radial distance was less than 3 d, and the excess pore water pressures induced by the drilling stage were all less than 55 kPa when the radial distance reached 4–6 d. The drilling process also induced some lateral soil pressure increases in the soil within a radial distance of 3 d, while the measured maximum lateral soil pressure increases were smaller than 10.9 kPa when the radial distance increased to 4 d. On the whole, the excess pore water pressures and lateral soil pressure increases induced by the installation of PGP pile were much smaller than that induced by the installation of driven PHC pile. Moreover, the horizontal soil displacements, excess pore water pressures and lateral soil pressure increases induced by the installation of PGP pile all recovered rapidly after the installation of pile, as the cemented soil in the pile hole was in liquid state after the drilling and grouting stage.

Application of GA-BP in Displacement Force Inverse Analysis and Mechanical Parameter Inversion of Deep Foundation Pits

Aiming at the defects of various existing displacement inverse analysis methods, using the nonlinear mapping ability of neural network and the global random search ability of genetic algorithm, this paper proposes a displacement inverse analysis method based on optimized Genetic Algorithm- Back Propagation (GA-BP) for deep foundation pit support. The method changes the method that BP algorithm relies on the guidance of gradient information to adjust the network weights, but uses the characteristics of global search of genetic algorithm to find the most suitable network connection rights and network structure, etc. to achieve the purpose of optimization. Firstly, the deformation mechanism of deep foundation pit is analyzed, its failure mode is summarized, and the calculation method of lateral rock and soil pressure is sorted out according to the code. The theory and characteristics of BP neural network and genetic algorithm are discussed, and the method of using genetic algorithm to optimize BP neural network is proposed to improve the prediction accuracy. In view of the shortcomings of GA-BP neural network prediction model in training sample pretreatment and hidden layer structure design, the optimal normalization interval was determined by correlation coefficient regression analysis, and the analytical expression of the number of neurons in hidden layer was derived by statistical principle, and the value range of the optimal number of neurons in single hidden layer was proposed. Combined with the actual engineering, the mechanical parameters inversion and displacement force inverse analysis are performed using this method, and the results show that the optimized GA-BP has higher prediction accuracy compared with BP neural network and GA-BP, and the deviation of the displacement prediction value at each depth is kept within 0.2 mm, the absolute error interval width is 0.07 mm, and the maximum relative error is 1.35% at 4.0 m depth.

Additional Lateral Soil Pressure on Soil due to The Vehicle at a Constant Speed

On roads that cross the slope is often required evaluation of the need for retaining slope construction (road). In the design of the construction, one of the main factors that must be known is the amount of horizontal ground pressure that occurs. The amount of ground pressure consists of the ground pressure it self and the pressure due to other loads such as vehicles passing on it. The horizontal pressure due to constant and stationary loads is different from the horizontal pressure due to a running vehicle. This study was conducted to determine how the additional influence of horizontal pressure that occurs due to the vehicle through on it. A model (vehicle) is simulated to move at a constant speed along a sensor-Fed trajectory at a predetermined position. Instrumentation results show that the additional pressure that occurs in the form of pressure bubbles is similar to the pressure due to stationary and constant vertical loads. Test results for low-speed loads below 10 km/hrs showed the greatest horizontal pressure that occurs at a depth of 0.5 m and a distance of 0.5 m from the instrumentation. A comparison using the Boussinesq equation using the same load, shows that the maximum horizontal pressure that occurs is still relatively smaller than the additional lateral pressure due to static load.

Comparative Analysis of Riverbanks Retrofitting Planning Using Strauss Pile and Ground Anchor

This research was conducted to reinforce the sheet pile located on the embankment of the Ciliwung Lama river – Inspection Road (RSCM) in Central Jakarta. The road is beside the riverbanks of the collapsed river for 40 m and the position of the sheet pile that slopes towards the river. Based on field observations and analysis of the stability of the slopes carried out, the road’s collapse was not due to the unstableness of the embankment but due to the inability of the sheet pile to receive lateral soil pressure. The research method used Plaxis 2D Software to analyze the reinforcement applied to the sheet pile in withstanding lateral soil pressure. The planned reinforcement of the sheet pile uses a Strauss pile with a sling and ground anchor. In retrofitting, using a Strauss pile, a diameter of 0.4 meters, a length of 9 meters, and a sling with a diameter of D32 with a distance between slings of 2.5 meters. Ground Anchor retrofitting is planned to be 27 m long, 159 mm in diameter, and 88 mm in body grout. Compared to the Safety Factor that occurs between the Strauss pile with the sling and the ground anchor, the safety factor of the Strauss pile with the sling is greater. The Strauss pile’s safety factor was obtained by 1.75, while the ground anchor safety factor was 1.55 without considering the earthquake load.

Mechanical Property of Lateral Piles for Pile Composite Foundation Loaded by Model Test

Under vertical load, the composite foundation may be damaged due to insufficient lateral restraint capacity. If the lateral restraint pile is added to the edge of the composite foundation, the lateral stability can be effectively enhanced. This new reinforcement scheme is called a combined composite foundation. For the combined composite foundation, the lateral restraint piles will bear a certain force when the composite foundation is loaded, and the force may cause the piles horizontal displacement, instability, or even failure. After preload on the composite foundation, the mechanical behavior of lateral restraint piles will be more sophisticated. To study the mechanical behavior of lateral restraint piles under such condition, a laboratory model test was conducted. The results are suggested as follows: Axial force distribution curves tend to be “S” shape with two peak values at the upper and lower parts, respectively. The negative axial force is distributed at the upper part, and the positive axial force is distributed at the lower part. The bending moment and lateral soil pressure distribution of piles appear with the regularity of “increase-decrease” along the depth. Such a phenomenon is associated with the expansion of a potential slip surface. In accordance with the relative location of the potential slide surface and the piles, the lateral restraint piles can fall into three sections. Different sections get different stresses. The reinforcement scopes have an impact on the stress of different lateral restraint piles. With the increase of the reinforcement scope, the axial force, soil pressure, and bending moment show the regularity of increase. The values of axial force, the lateral soil pressure, and the bending moment increase with load growth and become stable when the load is larger than 60 kN. This is associated with the piles in the composite foundation, which verifies the reinforcement effect to prevent the soil slide and the foundation deformation.

Parametric Studies for Steel Sheet Pile Wall Using GE05FINE

Abstract: Based on the site conditions and lateral earth pressure of soil plays important role in the selection of sheet pile wall. In the present day different types of sheet pile wall present in the market like as steel sheet pile wall , concrete sheet pile wall and timber etc. Concrete sheet pile walls are common in use. Modification in the properties of the concrete sheet piles is easier making it more economical as the utility of the section can be considerably increased according to projects requirement. Sheet pile wall deformation is dependent on the materials properties. Consequently, it is essential to research how different material types and properties affect the deformation and stress distribution of cantilever concrete sheet pile walls. A parametric analysis was carried out numerically using a case study that makes use of a base model to determine how long a sheet pile wall should be at the bottom of an embankment with various material types for ditch with a depth of 3m, 5m and 7m.to safeguard and improve the stability of the embankment , a sheet pile wall was temporarily constructed near the toe of the embankment. Analysing simulation data was completed with the aid of GE05FINE. The analysis findings revealed that when subjected to the same loading situation, bending moment and shear force varies with the material properties. Therefore, it is wise to carefully select the sheet pile wall materials in accordance with the projects requirements.

Parametric Studies for Concrete Sheet Pile Wall Using GE05FINE

Abstract: Based on the site conditions and lateral earth pressure of soil plays important role in the selection of sheet pile wall. In the present day different types of sheet pile wall present in the market like as steel sheet pile wall , concrete sheet pile wall and timber etc. Concrete sheet pile walls are common in use. Modification in the properties of the concrete sheet piles is easier making it more economical as the utility of the section can be considerably increased according to projects requirement. Sheet pile wall deformation is dependent on the materials properties. Consequently, it is essential to research how different material types and properties affect the deformation and stress distribution of cantilever concrete sheet pile walls. A parametric analysis was carried out numerically using a case study that makes use of a base model to determine how long a sheet pile wall should be at the bottom of an embankment with various material types for ditch with a depth of 3m, 5m and 7m.to safeguard and improve the stability of the embankment , a sheet pile wall was temporarily constructed near the toe of the embankment. Analysing simulation data was completed with the aid of GE05FINE. The analysis findings revealed that when subjected to the same loading situation, bending moment and shear force varies with the material properties. Therefore, it is wise to carefully select the sheet pile wall materials in accordance with the projects requirements.

Evaluation of Liquefaction-induced Lateral Force on Pile in Slope by Centrifuge Tests

Pile foundations in liquefied ground may be subjected to a substantial force induced by lateral soil movement, which is crucial in the seismic design of pile-supported structures. Thus, this study aims to investigate the liquefaction-induced lateral force to piles by conducting centrifuge tests. Pile–deck systems installed in liquefiable finite slope with an angle of 27° were constructed and tested with different base motions. Results show that the liquefied slope pushes the piles toward the downslope, causing a large bending moment. The linear and uniform distributions of lateral soil pressure, which have been previously suggested for pile analysis in liquefied ground, were examined and compared with the measured maximum bending moment. The linear soil pressure profile reasonably predicted the bending moment compared to the results of the uniform profile. The empirical gradient factor of the linear profile was calibrated for the single piles and then implemented in the pile group analysis. The calibrated factor improved conventional methods for predicting the bending moment profile of group piles.

Hyperbolic stress-strain behaviour of sandy soil under plane strain unloading condition and its application on predicting displacement-dependent active earth pressure

This study investigates the displacement-dependent lateral earth pressure of sandy soil in active state. 3D DEM numerical simulations of plane strain unloading test (unloading in the minor principal stress direction) are carried out firstly to acquire the hyperbolic stress–strain relationship of sandy soil. The initial modulus of sandy soil is observed to increase with the increasing of major principal stress, initial lateral earth pressure coefficient and relative density, while the failure ratio is little influenced by these factors. A simplified hyperbolic model calibrated by the DEM results are then developed to calculate the displacement-dependent active lateral earth pressure of sandy soil. It was found that the hyperbolic model can well predict the variation of lateral earth pressure distribution at intermediate active state of T- (Translation) and RB- (Rotate about the base) mode of retaining structure movement. But it can hardly capture the lateral earth pressure distribution on retaining structure under RT- (Rotate about the top) mode due to significant rotation of principal stress direction. According to the theoretical analysis, the required retaining structure displacement leading to the limiting active state is varied along the retaining structure, and it also dependents on the initial stress state as well as the relative density.

Improving bearing capacity using tire-derived-geo-cylinder – a haul road case study in Jalan Sikar Penajam Paser

This paper showcases a potential solution to improve soil bearing capacity using tire-derived-geo-cylinder (TDGC). TDGC uses used tires to provide confining pressure and tensile strength, hence improving the soil’s bearing capacity. The solution is applied for a haul road project on Jalan Sikar Penajam Paser. The site is frequently passed by large vehicles such as large trucks for the transportation of wooden logs and other heavy equipment. The tires used for TDGC are used tires of type LT245/75R16, which has a standard rim of 16 mm, a tire width of 248 mm, and an overall diameter of 780 mm. This category of tires has a load index of 1250-1600 kg. The load index is the value representing the tire's capacity to withstand load. The improvement in bearing capacity is evaluated using dynamic cone penetrometer (DCP) tests. In addition, the DCP tests were also used to interpret the Californian Bearing Ratio (CBR) values. The results show that without TDGC, the average CBR value is only 4.7%. In contrast, with TDGC, the average CBR increased to 17.2%, an increase of 265%. The CBR value obtained with TDGC places the soil into fair category for Subbase course. The average bearing capacity value obtained before TDGC was about 75 kN/m2 and with TDGC, the soil experienced a significant increase in bearing capacity value to 245 kN/m2. The increase of bearing capacity and CBR value from application of TDGC are due to the combination of the tires and stone fill. The tires provide tensile strength to resist lateral soil pressure as well as increased confining pressure, hence increasing the compressive strength.

Synthetic experimental and numerical investigation on the vertical seismic effect on underground structures

Seismic damage patterns of underground structures indicate unignorable effects of vertical seismic actions. To deal with this, this study distinguished the impact of the vertical seismic effect on the seismic safety of underground structures experimentally and theoretically and provides important shaking table test results for this topic. A typical shallow buried subway station-tunnel junction structure was designed by following the Buckingham similarity law, based on which the shaking table test was performed to investigate the vertical seismic effect on underground structures. The vertical wave propagation laws of the free field, the model structure, and the soil–structure interaction (SSI) system were comparatively analyzed. Numerical simulations considering the soil’s nonlinear behaviors under vertical loads were performed using the equivalent linear analysis method and were verified by the test records. By combining both the experimental and numerical results, it was found that the surrounding soils have very weak constraints on the structural vertical movements. By distinguishing lateral soil pressures from horizontal actions, the vertical seismic action is found to be mainly an inertia force that can stimulate high-frequency vibration modes of the system and cause considerable vertical relative deformations within the underground structure. Consistent with the observed structural damage at the Daikai station, the participation of high-frequency vibration modes is a rational approach that can explain the amplification effect of vertical ground motions on structural seismic responses. In addition, the equivalent linear method is generally satisfactory for simulating the soil compressional nonlinearity.

Application of a damage constitutive model to pile–slope stability analysis

Piles were regarded as elastic materials in the traditional numerical simulation. The elastic pile would not reflect the damage of the pile in engineering, which would misjudge the reinforcement effect of piles on slopes. The specific objective of this study was to propose a damage constitutive model to replace the traditional elastic constitutive model in the numerical analysis of pile–slope stability. In this study, the pile was simulated by a damage constitutive model, which can reflect the plastic deformation of the pile. The factors of pile position and reinforcement ratio on a slope’s factor of safety (FOS) are investigated by the finite difference method using FLAC3D. The lateral displacement, bending moment, shear force, and soil pressure of balance-reinforced piles are used to study the difference between damage and elastic constitutive models. The results showed that the FOS considering the damage constitutive model could be smaller, approximately 15% less than that considering an elastic constitutive model under specific conditions. Furthermore, the difference between the two evaluation results of the internal force of the same pile can reach about 30%. It was observed that the elastic constitutive model would overestimate the reinforcement effect of the pile on the slope, which will cause potential safety hazards in engineering. This study provides a realistic damage constitutive model for the design and evaluation of slope-stabilizing piles.