scholarly journals Lateral Response of a Single Pile under Combined Axial and Lateral Cyclic Loading in Sandy Soil

2018 ◽  
Vol 4 (9) ◽  
pp. 1996 ◽  
Author(s):  
Muqdad Abdallah Kahribt ◽  
Jasim M. Abbas
Keyword(s):  
Lateral Displacement ◽  
Slenderness Ratio ◽  
Offshore Structures ◽  
Lateral Loading ◽  
Loading Conditions ◽  
Lateral Loads ◽  
Dense Sand ◽  
Lateral Response ◽  
Loading System ◽  
Vertical Displacements

According to practical situation, there have been limited investigations on the response of piles subjected to combined loadings especially when subjected to cyclic lateral loads. Those few studies led to contradictory results with regard to the effects of vertical loads on the lateral response of piles. Therefore, a series of experimental investigation into piles in dense sand subjected to combination of static vertical and cyclic lateral loading were conducted with instrumented model piles. The effect of the slenderness ratio (L/D) was also considered in this study (i.e. L/D= 25 and 40). In addition, a variety of two-way cyclic lateral loading conditions were applied to model piles using a mechanical loading system. One hundred cycles were used in each test to represent environmental loading such as offshore structures. It was found that under combined vertical and cyclic lateral loads the lateral displacement of piles decreased with an increase in vertical load whereas it causes large vertical displacements at all slenderness ratios. In addition, for all loading conditions the lateral, vertical (settlement and upward) displacements and bending moments increased as either the magnitude of cyclic load or the number of cycles increases. 

scholarly journals Lateral Performance for Long Pile Subjected to Simultaneous Axial and Lateral Loads in Dense Sand: An Experimental Study

2019 ◽  
Vol 12 (2) ◽  
pp. 110-114
Author(s):  
Jasim M. Abbas
Keyword(s):  
Experimental Study ◽  
Slenderness Ratio ◽  
The Other ◽  
Laboratory Model ◽  
Single Pile ◽  
Lateral Loads ◽  
Dense Sand ◽  
Other Hand ◽  
Pile Response

The present study focus on the investigation ofthe response of single pile when subjected to both axial and lateral loads simultaneously in dense sand. To study this issue, laboratory model was locally improved to examine the piles under this kind of loading. The dense sand provided using raining technique. The slenderness ratio of the tested pile is ( L/D=45). On the other hand, the vertical and horizontal loads are divided into 5 stages to assess the influence of load intensities on the lateral pile response. It can be concluded that the lateral pile response is affected by changing the load intensities

scholarly journals A Numerical Analysis on the Behavior of Single Battered Pile under Pullout Loading

2021 ◽  
Vol 318 ◽  
pp. 01010
Author(s):  
Mais S. Al-Tememy ◽  
Mohammed A. Al-Neami ◽  
Mohammed F. Asswad
Keyword(s):  
Three Dimensional ◽  
Bending Moment ◽  
Offshore Structures ◽  
Pullout Capacity ◽  
Element Analysis ◽  
Dense Sand ◽  
Dimensional Finite Element ◽  
Pullout Load ◽  
Three Dimensional Finite Element ◽  
3D Software

Batter or raker piles are piles driven at an inclination with a vertical to resist large inclined or lateral forces. Many structures like offshore structures and towers are subjected to overturning moments due to wave pressure, wind load, and ship impacts. Therefore in such structures, a combination of the vertical and batter piles is used to transfer overturning moments in compression and tension forces to the foundation. This paper presents a three-dimensional finite element analysis using PLAXIS 3D software to study the battered pile's behavior under the effect of pullout load. Several variables that influence the pile tension capacity embedded in sandy soil are investigated. The pile models are steel piles embedded in the dense sand at different batter angles (0, 10, 20, and 30) degrees with two embedment ratios, L/d (15 and 20). To clarify the pile shape's influence on a pullout capacity, two shapes are used, a circular pile with a diameter equal to 20 mm and a square pile with a section of 15.7×15.7 mm. These dimensions are chosen to achieve an equal perimeter for both shapes. The numerical results pointed that the pile pullout capacity increases with the increasing of the batter angle and embedment ratio, and the maximum values are marked at a batter angle of 20o. The shape of the bending moment profile is a single curvature, and the peak values are located approximately at the midpoint of the battered pile, while a zero value is located at the pile tip and pile head.

Three-Dimensional Nonlinear Stability Analysis of Tangent Continuous Welded Rail Track Under Temperature and Mechanical Loads

1997 ◽  
Vol 1584 (1) ◽  
pp. 31-40 ◽  
Author(s):  
Yulin Bao ◽  
Ernest J. Barenberg
Keyword(s):  
Stability Analysis ◽  
Lateral Displacement ◽  
Three Dimensional ◽  
Initial Slope ◽  
Lateral Loads ◽  
Rotational Stiffness ◽  
Geometric Imperfections ◽  
Mechanical Loads ◽  
Lateral Resistance ◽  
Continuous Welded Rail

Results from applications of the three-dimensional continuous welded rail (CWR) track model ILLIBUCKLE to a tangent CWR track with nonlinear resistance and lateral geometric imperfections are presented. Stability analysis is made of the tracks under temperature and mechanical loads by using temperature lateral-displacement curves. Tangent CWR track stability is highly sensitive not only to ballast lateral resistance and geometric imperfections of the the initial track but also to the vertical rotational stiffness in rail-pad fastener systems and vehicle lateral loads. It is concluded that not only the peak values but also the initial slope and the limit resistance in the ballast lateral-resistance curve obtained from a single-tie push test are important in evaluation of track stability. With regard to vertical rotational stiffness in a rail-pad fastener system, track stability is not significantly affected by the nonlinearities, but it is affected by the initial slope. Effects of the combination of mechanical and thermal loads on tangent track stability are presented. The reduction of ballast lateral resistance due to the uplift of rail tie under vehicle vertical loads as well as the magnitude of vehicle lateral loads significantly decrease track stability. A 1400-kg vehicle lateral load can buckle tangent CWR track under a rail-temperature increase as low as 56°C (100°F) under unfavorable conditions.

Performance-Based Pushover Cyclic Test For Innovative Prefabricated Hybrid Industrialised Building System Sub-Frame

2015 ◽  
Vol 74 (1) ◽  
Author(s):  
Wong Jing Ying ◽  
Abdul Kadir Marsono ◽  
Masine Md. Tap ◽  
Chun-Chieh Yip
Keyword(s):  
Lateral Displacement ◽  
Load Test ◽  
Structural Performance ◽  
Hysteresis Curve ◽  
Lateral Loads ◽  
Structural Behaviour ◽  
Displacement Ductility ◽  
Building System ◽  
Immediate Occupancy ◽  
Set Up

The paper presents a pseudo-dynamic cyclic load test to evaluate the structural performance of innovative prefabricated hybrid Industrialised Building System (IBS) subjected to earthquake-induced ground motions. Two beams, three columns and six wall panels with scale of 1:5 were casted using concrete grade 30. Steel bars with diameters of 6 mm and 1.5 mm were used as main reinforcement and links, respectively. The frame was set-up and tested in two reversal directions of cyclic lateral loads in the structural laboratory. Eight Linear Variable Displacement Transducers (LVDTs) and seven strain gauges were instrumented in the model to record deflections and strains. This experiment was conducted in displacement-controlled mode. Four cycles of loads were applied corresponding to the initial targeted lateral displacement to obtain hysteresis curve. The structural performance was assessed using structural seismic demand parameters such as story displacement, displacement ductility and energy dissipation. Three structural performance levels that were Immediate Occupancy (IO), Life Safety (LS) and Collapse Prevention (CP) were assessed with compliance of FEMA 356. Structural behaviour, localised stressed and failed components were checked and recorded. The experimental results were presented in load-displacement of the system, mapped crack patterns, and development of capacity curve. Damage ranking were proposed based on degree of damage of scaled 1:5 of SMART IBS frame. 

Experimental evaluation of the lateral load distribution in the elastic-plastic phase of timber-steel hybrid structures with a novel light timber-steel diaphragm

2019 ◽  
Vol 22 (8) ◽  
pp. 1965-1976
Author(s):  
Zhong Ma ◽  
Minjuan He ◽  
Renle Ma ◽  
Zheng Li ◽  
Linlin Zhang
Keyword(s):  
Load Distribution ◽  
Failure Modes ◽  
Lateral Displacement ◽  
Lateral Load ◽  
Lateral Loads ◽  
Distribution Factor ◽  
Elastic Plastic ◽  
Plastic Phase ◽  
Lateral Load Distribution ◽  
Load Distribution Factor

A cyclic loading experiment involving a timber-steel hybrid structure consisting of a steel frame and a novel light timber-steel diaphragm is presented to quantify the flexibility of the diaphragm and its ability to distribute lateral loads in the elastic-plastic phase of the structure. A lateral load-distribution factor was proposed, and its relationship to the ratio of the stiffness of the diaphragm to that of the lateral load-resisting elements was investigated. The diaphragm was classified based on these variables. The results indicated that the failure modes of the structure were associated with the forms of damage experienced by the lateral load-resisting elements, whereas little damage was observed for the diaphragm. The diaphragm exhibited the ability to continuously adjust the distribution of lateral loads to each lateral load-resisting element; accordingly, each lateral load-resisting element had approximately the same shear force, the same lateral stiffness, and the same lateral displacement during the loading process. As the lateral displacement increased, the stiffness ratio and load-distribution factor both gradually increased, and the diaphragm correspondingly changed from semi-rigid to rigid. At times, as the lateral displacement increased, the diaphragm rapidly became rigid, and it was unnecessarily rigid during the initial loading phase when the in-plane stiffness reached a certain threshold.

Influence of lateral loading direction on the peak shear strength of non-rectangular reinforced concrete squat walls

2019 ◽  
Vol 22 (11) ◽  
pp. 2392-2405 ◽  
Author(s):  
Jiaxing Ma ◽  
Bing Li
Keyword(s):  
Shear Strength ◽  
Reinforced Concrete ◽  
Seismic Waves ◽  
Lateral Loading ◽  
Peak Shear Strength ◽  
Lateral Loads ◽  
Structural Walls ◽  
Finite Element Software ◽  
Loading Direction ◽  
Squat Walls

Peak shear strength is a critical parameter in the evaluation of the seismic performance of structural walls. Different equations have been proposed to predict the peak shear strength of reinforced concrete squat walls in literature, which assume lateral loading is parallel to the web. In reality, however, seismic waves can reach structures from any direction, which necessitates the studies on the behavior of structural walls under various lateral loading directions. Unlike rectangular walls, non-rectangular walls naturally possess the capacity to resist lateral loads in both transverse and longitudinal directions. To explore the peak shear strength of such walls under different lateral loading directions, a widely used nonlinear finite element software Diana 9.4 was utilized in this article. Appropriate modeling approaches were first selected and further validated by simulating relevant experiments. Then a comprehensive parametric study was carried out to investigate the influence of lateral loading directions and other important parameters.

scholarly journals Flexible Pile Group Interaction Factors under Arbitrary Lateral Loading in Sand

2020 ◽  
Vol 8 (10) ◽  
pp. 800
Author(s):  
Miloš Marjanović ◽  
Mirjana Vukićević ◽  
Diethard König
Keyword(s):  
Numerical Study ◽  
Group Interaction ◽  
Pile Group ◽  
Lateral Loading ◽  
Soil Conditions ◽  
Offshore Platforms ◽  
Lateral Loads ◽  
Pile Groups ◽  
Main Hypothesis ◽  
Interaction Factors

Marine and harbor structures, wind turbines, bridges, offshore platforms, industrial chimneys, retaining structures etc. can be subjected to significant lateral loads from various sources. Appropriate assessment of the foundations capacity of these structures is thus necessary, especially when these structures are supported by pile groups. The pile group interaction effects under lateral loading have been investigated intensively in past decades, and the most of the conducted studies have considered lateral loading that acts along one of the two orthogonal directions, parallel to the edge of pile group. However, because of the stochastic nature of its source, the horizontal loading on the pile group may have arbitrary direction. The number of studies dealing with the pile groups under arbitrary loading is very limited. The aim of this paper is to investigate the influence of the arbitrary lateral loading on the pile group response, in order to improve (extend) the current design approach for laterally loaded pile groups. Free head, flexible bored piles in sand were analyzed through the extensive numerical study. The main hypothesis of the research is that some critical pile group configurations, loading directions, and soil conditions exist, which can lead to the unsafe structural design. Critical pile positions inside the commonly used pile group configurations are identified with respect to loading directions. The influence of different soil conditions was discussed.

Response of tapered piles subjected to lateral loading

1999 ◽  
Vol 36 (1) ◽  
pp. 52-71 ◽  
Author(s):  
M Hesham El Naggar ◽  
Jin Qi Wei
Keyword(s):  
Large Scale ◽  
Bending Moment ◽  
Average Diameter ◽  
Confining Pressure ◽  
Lateral Loading ◽  
Cohesionless Soil ◽  
Lateral Loads ◽  
Moment Functions ◽  
Measured Strain ◽  
Displacement Transducers

Eighteen lateral loading tests were conducted on large-scale steel piles to establish the lateral behaviour of tapered piles in cohesionless soil. Three piles 1.52 m in length with different taper angles but the same average embedded diameter of 168 mm were installed in sand enclosed in a steel chamber 1.5 m in diameter and 1.445 m in depth. The soil chamber was lined with an air bladder so that sand inside the chamber could be pressurized to vary the confining pressure. The piles were instrumented with electrical resistance strain gauges and the horizontal pile movements at grade and the loading point were measured with displacement transducers. The bending-moment functions along the pile were calculated from the strain measurements by curve fitting the measured strain data. The soil resistance (p) and pile displacement (y) relationships were developed in the form of p-y curves by differentiating and integrating these bending-moment functions. It was found that tapered piles carried up to 77% more lateral loads than straight-sided-wall piles with the same average diameter. The maximum bending moment occurred in all piles at almost the same depth of one third of the embedded length of the pile. Hence, the cross section of tapered piles at the location of maximum bending moment was larger than that of straight-sided-wall piles, resulting in lower stresses in the pile. It was concluded that the tapered piles represent a more efficient distribution of the pile material and display better performance under lateral loading conditions.Key words: tapered piles, lateral response, p-y curves, modulus of subgrade reaction.

Non-Linear Step-by-Step Seismic Response and the Push-Over Analysis Comparison of a Reinforced Concrete of Ductile Frames 15 Level Building

2008 ◽  
Vol 385-387 ◽  
pp. 229-232
Author(s):  
Jorge A. Avila ◽  
Eduardo Martínez
Keyword(s):  
Lateral Displacement ◽  
Time History ◽  
Seismic Zone ◽  
Lateral Loads ◽  
Base Shear ◽  
Non Linear ◽  
Story Drift ◽  
Lateral Displacements ◽  
Group B ◽  
Level Building

Based on a ductile frames 15 level building, a non-linear analysis with increased monotonically lateral loads (Push-Over) was made in order to determine its collapse and its principal responses were compared against the elastic and inelastic time-history seismic responses determined with the SCT-EW-85 record. The seismic-resistance design and faced to gravitational loads was made according to the Complementary Technical Norms of Concrete Structures Design (NTC-Concrete) and the NTC-Seismic of the Mexico City Code (RDF-04), satisfying the limit service states (relative lateral displacement between story height maximum relations, story drifts ≤ 0.012) and failure (seismic behavior factor, Q= 3). The compressible (soft) seismic zone IIIb and the office use type (group B) were considered. The non-linear responses were determined with nominal and over-resistance effects. The comparison were made with base shear force–roof lateral displacement relations, global distribution of plastic hinges, failure mechanics tendency, lateral displacements and story drift and its distribution along the height of the building, local and global ductility demands, etc. For the non-linear static analysis with increased monotonically lateral loads, it was important to select the type of lateral forces distribution.

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