RAPID LOAD TESTING OF STONE COLUMNS TO AID DESIGN OF FOUNDATIONS ON IMPROVED GROUND

2018 ◽  
Vol 5 (1) ◽  
Author(s):  
John Fahd Touma ◽  
Salah Sadek ◽  
Shadi Najjar
Keyword(s):  
Static Load ◽  
Ground Improvement ◽  
Compressive Force ◽  
Field Tests ◽  
Site Investigation ◽  
Shallow Foundations ◽  
Load Test ◽  
Stone Columns ◽  
Load Testing ◽  
Axial Compressive Force

Building Codes and best practice require load testing of embedded structural foundation elements to validate design and construction execution quality. This requirement is particularly challenging when associated with ground improvement schemes relying on granular reinforcing/stone columns. Stone columns present an economic solution for improving the bearing capacity of shallow foundations on soft soils. A novel impulse load test was developed and used to quantify the load-displacement response of shallow foundations supported on stone columns at a clay site. The device is referred to as the Rapid Plate Load Tester (RPLT) and is a modified version of the Axial Compressive Force Pulse test for deep foundations. In this paper, the comprehensive site investigation, stone columns construction, load testing procedure, and data analysis are described. Static and dynamic field tests were performed to target loads of 2000 kN and equivalent bearing pressures of 500kPa. The results obtained from the RPLT tests were used to derive equivalent static load settlement curves for footings on both the natural clay ground and improved ground and compared with the results obtained from the full-scale static load tests.

scholarly journals Calculation of Pile Side Friction by Multiparameter Statistical Analysis

2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Zhijun Zhou ◽  
Yaqin Dong ◽  
Peijun Jiang ◽  
Dandan Han ◽  
Tong Liu
Keyword(s):  
Statistical Analysis ◽  
Static Load ◽  
Load Test ◽  
Load Testing ◽  
Analysis Method ◽  
Static Load Test ◽  
Statistical Analysis Method ◽  
Loess Region ◽  
Side Friction ◽  
Static Load Testing

In this paper, a static load test and a multiparameter statistical analysis method are used to study the value of pile side friction in different soil layers in a loess region. Currently, static load testing is the most commonly used method to determine the bearing capacity of pile foundation. During the test, a vertical load is applied at the top of the pile, the data under each load level are recorded, and a Q-S curve is drawn to obtain the ultimate bearing capacity of a single pile. Reinforcement stress gauges are installed at different sections of the pile body, and then the axial force and the pile side friction of each section are calculated. Few studies have investigated the calculation of pile side friction in different soil layers using the multiparameter statistical analysis method. Obtaining accurate results using this method will provide an important supplement to the calculation of pile side friction and will also be conducive to the development of theoretical calculation of pile side friction. Therefore, taking Wuding Expressway project in loess region as an example, the lateral friction resistance of six test piles is studied through static load testing and multiparameter statistical analysis. The multiparameter statistical analysis method is compared with the static load test results, and the error is controlled within 20%. The results show that the calculation results of multiparameter statistical analysis essentially fulfill engineering requirements.

scholarly journals Limitations and risk related to static capacity testing of piles – “unfortunate case” studies

2018 ◽  
Vol 146 ◽  
pp. 02006 ◽  
Author(s):  
Jarosław Rybak ◽  
Maciej Król
Keyword(s):  
Field Tests ◽  
Horizontal Displacement ◽  
Load Test ◽  
Load Testing ◽  
Key Factors ◽  
Pile Head ◽  
Load Range ◽  
Lateral Capacity ◽  
Vertical Loading ◽  
The Impact

Static load testing of foundation piles is still considered the main capacity check technology for almost any kind of piling works (bored, displacement, driven). The rates of load, time increments or imposed displacement are the key factors for various testing methods. The load-displacement relationship, which can be transformed into a coordinate system, is always the point of departure for the analysis of the results. For axis (vertical) loading, both, applied load and measured pile head settlement are examined during the entire test. During the lateral capacity tests, the horizontal displacement and inclination of free pile head is measured. In either case, all recorded values must be thoroughly examined in order to avoid systematic errors which could flaw the results of the analysis. In this paper, the authors gather and discuss their experience from field tests in which equipment malfunctions or external circumstances had the impact on the range of load test and, thus, their results. The possible ways of test extrapolation with regard to load range are also the subject of further observations presented in this publication.

scholarly journals Geodetic monitoring of bridge deformations occurring during static load testing

2015 ◽  
Vol 10 (1) ◽  
pp. 17-27 ◽  
Author(s):  
Tarvo Mill ◽  
Artu Ellmann ◽  
Martti Kiisa ◽  
Juhan Idnurm ◽  
Siim Idnurm ◽  
...  
Keyword(s):  
Laser Scanning ◽  
Static Load ◽  
Terrestrial Laser Scanning ◽  
Deformation Monitoring ◽  
Load Test ◽  
Load Testing ◽  
Static Load Test ◽  
Study Results ◽  
Extreme Load ◽  
Load Tests

Terrestrial laser scanning technology has developed rapidly in recent years and has been used in various applications but mainly in the surveying of different buildings and historical monuments. The use for terrestrial laser scanning data for deformation monitoring has earlier been tested although conventional surveying technologies are still more preferred. Since terrestrial laser scanners are capable of acquiring a large amount of highly detailed geometrical data from a surface it is of interest to study the metrological advantages of the terrestrial laser scanning technology for deformation monitoring of structures. The main intention of this study is to test the applicability of terrestrial laser scanning technology for determining range and spatial distribution of deformations during bridge load tests. The study presents results of deformation monitoring proceeded during a unique bridge load test. A special monitoring methodology was developed and applied at a static load test of a reinforced concrete cantilever bridge built in 1953. Static loads with the max force of up to 1961 kN (200 t) were applied onto an area of 12 m² in the central part of one of the main beams; the collapse of the bridge was expected due to such an extreme load. Although the study identified occurrence of many cracks in the main beams and significant vertical deformations, both deflection (–4.2 cm) and rising (+2.5 cm), the bridge did not collapse. The terrestrial laser scanning monitoring results were verified by high-precision levelling. The study results confirmed that the TLS accuracy can reach ±2.8 mm at 95% confidence level.

scholarly journals TLS Measurement during Static Load Testing of a Railway Bridge

2019 ◽  
Vol 8 (1) ◽  
pp. 44 ◽  
Author(s):  
Pelagia Gawronek ◽  
Maria Makuch
Keyword(s):  
Laser Scanning ◽  
Static Load ◽  
Vertical Displacement ◽  
Load Test ◽  
Load Testing ◽  
Railway Bridge ◽  
Static Load Test ◽  
3D Data ◽  
Steel Railway Bridge ◽  
White Target

Terrestrial laser scanning (TLS) technology has become increasingly popular in investigating displacement and deformation of natural and anthropogenic objects. Regardless of the accuracy of deformation identification, TLS provides remote comprehensive information about the measured object in a short time. These features of TLS were why TLS measurement was used for a static load test of an old, steel railway bridge. The results of the measurement using the Z+F Imager 5010 scanner and traditional surveying methods (for improved georeferencing) were compared to results of precise reflectorless tacheometry and precise levelling. The analyses involved various procedures for the determination of displacement from 3D data (black & white target analysis, point cloud analysis, and mesh surface analysis) and the need to pre-process the 3D data was considered (georeferencing, automated filtering). The results demonstrate that TLS measurement can identify vertical displacement in line with the results of traditional measurements down to ±1 mm.

scholarly journals Assessment of the bearing capacity of piles during static load test

2020 ◽  
Vol 8 (4) ◽  
pp. 22-27
Author(s):  
Pavel Gavrilov ◽  
Vyacheslav Glukhov
Keyword(s):  
Bearing Capacity ◽  
Static Load ◽  
Field Tests ◽  
Load Test ◽  
Static Load Test ◽  
Static Tests ◽  
Standard Values ◽  
Bored Piles ◽  
The Moment ◽  
Experimental Researches

The purpose of this research is to estimate the bearing capacity of bored piles with broadening, formed by stone rolling. A series of static tests of the existing piles was performed in accordance with the requirements of the current regulatory documentation, the analysis of the obtained results was carried out. According to this experimental researches, was made a conclusion about the advisable to take into account the standard values of settlements at the determining of the bearing capacity of piles by ground. The results of field tests were compared with the calculated values, determined by calculation with the recommendations of SP 24.13330.2011. Noted, that the value of load, corresponding to the moment of the pile «failure», should be taken as a criterion of the factual bearing capacity.

A Load-Testing Program on Large-Diameter (66-Inch) Open-Ended and PSC-Instrumented Test Piles to Evaluate Design Parameters and Pile Setup

2018 ◽  
Vol 2672 (52) ◽  
pp. 291-306 ◽  
Author(s):  
Md. Nafiul Haque ◽  
Murad Y. Abu-Farsakh ◽  
Chris Nickel ◽  
Ching Tsai ◽  
Jesse Rauser ◽  
...  
Keyword(s):  
Static Load ◽  
Large Diameter ◽  
Load Test ◽  
Design Parameters ◽  
Soil Conditions ◽  
Load Testing ◽  
Static Load Test ◽  
Testing Program ◽  
Tip Resistance ◽  
Load Tests

This paper presents the results from a pile load testing program for a bridge construction project at Chalmette, Louisiana. The load testing includes three 66-in. spun-cast post-tensioned open-ended cylinder piles and one 30-in. square prestressed concrete (PSC) pile driven at four different locations along the bridge site in clayey-dominant soil. Both cone penetration tests and soil borings/laboratory testing were used to characterize the subsurface soil conditions. All test piles (TP) were instrumented with strain gauges to measure the load distribution along the length of the TPs and to measure the side and tip resistances, separately. Dynamic load tests (DLT) were performed on all TPs at different waiting periods after pile installations to quantify the amount of setup (i.e., increase in pile resistance with time). Case Pile Wave Analysis Program (CAPWAP®) analyses were performed on the DLT data to calculate the resistance distributions along the TPs. A static load test was performed only on the PSC pile and statnamic load tests (SNLT) were conducted on both pile types. Design parameters such as the total stress adhesion factor, α, and the effective stress coefficient, β, were back-calculated. The α values ranged from 0.41 to 0.86, and the β values ranged from 0.13 to 0.29. The load test results showed that SNLT overestimated the tip resistance as compared with dynamic and static load tests. Moreover, the pile tip resistance was almost constant during the testing period, and setup was mainly attributed to increase in pile side resistance with time.

Research of Static Load Testing Program of Reinforced Concrete Truss Scheme

2013 ◽  
Vol 443 ◽  
pp. 110-113
Author(s):  
Ying Xia
Keyword(s):  
Static Load ◽  
Test Site ◽  
Load Test ◽  
Load Testing ◽  
Static Load Test ◽  
Test Program ◽  
Loading Test ◽  
Static Loading Test ◽  
Testing Work ◽  
Static Load Testing

In order to ensure the safety of the truss, truss structure should be carried out prior to use static loading test for assessing the actual working conditions as well as the truss trusses meet the design. The static load test site carries out the testing work. In this paper loaded static load test program was designed to include load cases and measuring points on the truss static load test a theoretical analysis.

scholarly journals Numerical Modelling of Various Aspects of Pipe Pile Static Load Test

Energies ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 8598
Author(s):  
Michał Baca ◽  
Alexander L. Ivannikov ◽  
Jarosław Rybak
Keyword(s):  
Static Load ◽  
Numerical Models ◽  
Field Tests ◽  
Load Test ◽  
Test Field ◽  
Static Load Test ◽  
Pipe Pile ◽  
Pile Installation ◽  
New Process ◽  
Load Tests

Due to the development of dedicated software and the computing capabilities of modern computers, the application of numerical methods to analyse more complex geotechnical problems is becoming increasingly common. However, there are still some areas which, due to the lack of unambiguous solutions, require a more thorough examination, e.g., the numerical simulations of displacement pile behaviour in soil. Difficulties in obtaining the convergence of simulations with the results of static load tests are mainly caused by problems with proper modelling of the pile installation process. Based on the numerical models developed so far, a new process of static load test modelling has been proposed, which includes the influence of pile installation on the soil in its vicinity and modelling of contact between steel pile and the soil. Although the presented method is not new, this is relevant and important for practitioners that may want to improve the design of displacement piles. The results of the numerical calculations were verified by comparing them with the results of pipe pile field tests carried out in a natural scale on the test field in Southern Poland.

Comparison of the Bidirectional Load Test with the Top-Down Load Test

2005 ◽  
Vol 1936 (1) ◽  
pp. 108-116 ◽  
Author(s):  
Oh Sung Kwon ◽  
Yongkyu Choi ◽  
Ohkyun Kwon ◽  
Myoung Mo Kim
Keyword(s):  
Load Transfer ◽  
Measurement Data ◽  
Load Test ◽  
Load Testing ◽  
Pile Head ◽  
Top Down ◽  
Simple Method ◽  
Testing Method ◽  
Settlement Behavior ◽  
Cell Test

For the past decade, the Osterberg testing method (O-cell test) has been proved advantageous over the conventional pile load testing method in many aspects. However, because the O-cell test uses a loading mechanism entirely different from that of the conventional pile loading testing method, many investigators and practicing engineers have been concerned that the O-cell test would give inaccurate results, especially about the pile head settlement behavior. Therefore, a bidirectional load test using the Osterberg method and the conventional top-down load test were executed on 1.5-m diameter cast-in-place concrete piles at the same time and site. Strain gauges were placed on the piles. The two tests gave similar load transfer curves at various depth of piles. However, the top-down equivalent curve constructed from the bidirectional load test results predicted the pile head settlement under the pile design load to be approximately one half of that predicted by the conventional top-down load test. To improve the prediction accuracy of the top-down equivalent curve, a simple method that accounts for the pile compression was proposed. It was also shown that the strain gauge measurement data from the bidirectional load test could reproduce almost the same top-down curve.

Investigation of Grouted Coupler Connection Details for Accelerated Bridge Construction

2021 ◽  
pp. 036119812199939
Author(s):  
Brent Phares ◽  
Yoon-Si Lee ◽  
Travis K. Hosteng ◽  
Jim Nelson
Keyword(s):  
Crack Width ◽  
High Performance ◽  
Static Load ◽  
High Performance Concrete ◽  
Precast Concrete ◽  
Chloride Penetration ◽  
Load Testing ◽  
Test And Evaluation ◽  
Load Tests ◽  
Precast Elements

This paper presents a laboratory investigation on the performance of grouted rebar couplers with the connection details similar to those utilized on the precast concrete elements of the Keg Creek Bridge on US 6 in Iowa. The testing program consisted of a series of static load tests, a fatigue test, and evaluation of the chloride penetration resistance of laboratory specimens. The goal of this testing was to evaluate the ability of the grouted rebar couplers to develop flexural capacity at the joint between the precast elements as well as the durability of the connection. For structural load testing, seven full-scale specimens, each with #14 epoxy-coated rebars spliced by epoxy-coated grouted couplers, were fabricated and tested in three different loading cases: four-point bending, axial tension plus bending, and a cyclic test of the system in bending. The static load testing demonstrated that the applied axial load had a minimal effect on the formation of cracks and overall performance of the connection. When ultra-high performance concrete was used as a bedding grout, the initiation of crack was slightly delayed but no considerable improvement was observed in the magnitude of the crack width during loading or the crack closure on unloading. The results of the seventh specimen, tested in fatigue to 1 million cycles, showed little global displacement and crack width throughout the test, neither of which expanded measurably. No evidence of moisture or chloride penetration was detected at the grouted joint during the 6-month monitoring.

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