Interpreting Ultimate Capacity of Driven Piles with S-lgt Curve and Davisson Offset Limit

2011 ◽  
Vol 90-93 ◽  
pp. 121-127 ◽  
Author(s):  
Dong Yuan Wang ◽  
Jian Jun Zhao ◽  
Yu Ming Zhou ◽  
Li Qiang Lu
Keyword(s):  
Static Load ◽  
Soft Soil ◽  
Western World ◽  
Engineering Practice ◽  
Load Testing ◽  
Ultimate Capacity ◽  
Driven Piles ◽  
Concrete Pipe ◽  
Ground Conditions ◽  
Load Tests

This paper explores the methods used widely in China and western world interpreting the ultimate capacity of driven piles based on axial static load tests. A database consisting of 57 prestressed high- compression-capacity concrete pipe piles, which are widely used in soft soil ground conditions for building and transportation projects in China, is built. Two methods widely used in China and western world to interpret the ultimate capacity of driven piles based on axial static load testing data, S-lg(t) curve and Davisson Offset Limit, are applied to the database. Findings indicate that both methods work well and reach almost the same estimation. Conclusions suggest that both academia and industry of China and western world should take the advantages of the methods and apply them to engineering practice.

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.

scholarly journals Bi-Directional Static Load Tests of Pile Models

2020 ◽  
Vol 10 (16) ◽  
pp. 5492
Author(s):  
Michał Baca ◽  
Włodzimierz Brząkała ◽  
Jarosław Rybak
Keyword(s):  
Bearing Capacity ◽  
Static Load ◽  
Load Testing ◽  
Pile Capacity ◽  
Pile Shaft ◽  
Load Tests ◽  
S Curve ◽  
Definition Of ◽  
Standard Tests ◽  
Static Load Testing

This work examined a new method of bi-directional static load testing for piles, referencing the Osterberg test. Measurements were taken, on a laboratory scale, using six models of piles driven into a box filled with sand. This method allowed for separate measurements of pile base and pile shaft bearing capacities. Based on the results, the total pile bearing capacity and equivalent Q–s diagrams were estimated. The results obtained show that the structure of the equivalent curve according to Osterberg is a good approximation of the standard Q–s curve obtained from load tests, except for loads close to the limit of bearing capacity (those estimates are also complicated by the inapplicability and ambiguity of a definition of the notion of limit bearing capacity); the equivalent pile capacity in the Osterberg method represents, on average, about 80% of the capacity from standard tests.

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 Improving The Prediction For The Ultimate Axial Capacity Of Driven Piles In Ontario Soils With A Genetic Algorithm

2021 ◽  
Author(s):  
Markus Jesswein
Keyword(s):  
Genetic Algorithm ◽  
Influential Factors ◽  
Design Methods ◽  
Driven Piles ◽  
Compression Load ◽  
Axial Capacity ◽  
Side Resistance ◽  
Ground Conditions ◽  
Load Tests ◽  
Soil Measurements

A genetic algorithm (GA) was developed to improve predictions for the ultimate axial capacity of driven piles in Ontario soils. Challenges arise to accurately predict the ultimate capacity due to many influential factors, such as the ground conditions, installation method, and pile geometry. A total of 43 piles (H or pipe piles) were collected from the Ministry of Transportation of Ontario. Side and tip resistances were extracted from piles subjected to extension and compression load tests. The soil measurements and pile resistances were regressed with a statistical analysis and GA, and the developed relationships were compared to existing design methods. On average, existing design methods overestimated the capacity by a factor of 1.16 to 3.00. The proposed correlations were slightly conservative with the capacity but provided errors within ± 30 % of the measured side resistance. The new design methods from the GA offer substantial improvements for pile design

Estimating static tip resistance of driven piles with bottom pile instrumentation

2012 ◽  
Vol 49 (4) ◽  
pp. 381-393 ◽  
Author(s):  
Khiem T. Tran ◽  
Michael McVay ◽  
Rodrigo Herrera ◽  
Peter Lai
Keyword(s):  
Static Load ◽  
Accelerometer Data ◽  
Driven Piles ◽  
Unknown Parameters ◽  
Single Degree Of Freedom ◽  
Tip Resistance ◽  
Load Tests ◽  
Energy Equilibrium ◽  
Static Resistance ◽  
Time Assessment

A technique is presented to estimate static tip resistance of a pile during driving from embedded strain and accelerometer data located one diameter (D) from the bottom of the pile. The approach uses a nonlinear single degree of freedom system to satisfy force and energy equilibrium with a global genetic inversion approach. By balancing force and energy from inertia, damping, and stiffness against the measured tip data, the unknown parameters (mass, damping, and nonlinear stiffness) are estimated. Requiring a few seconds for analysis for each blow, the algorithm ensures a real-time assessment of static tip resistance as a function of displacement, which is important when setting pile lengths. The proposed approach was applied to four test piles at two bridge sites (Florida and Louisiana). Mobilized static tip resistances ranging from 400 to 1500 kN as a function of displacement were predicted. The predicted static resistance versus displacements compared favorably with measured values from static load tests. Interestingly, the maximum recorded increase in tip resistance in silty to clayey sands was less than 20% when piles were re-struck at times ranging from 2 to 30 days after initial drive.

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.

scholarly journals USING OF DYNAMIC AND STATIC LOAD PILING TESTS IN ASTANA, KAZAKHSTAN

2017 ◽  
Vol 2 (49) ◽  
pp. 32-37
Author(s):  
A. Z. Zhussupbekov ◽  
Z. A. Shakhmov ◽  
G. T. Tleulenova ◽  
S. B. Akhazhanov
Keyword(s):  
Bearing Capacity ◽  
Static Load ◽  
Precast Concrete ◽  
Load Test ◽  
Soil Conditions ◽  
Construction Sites ◽  
Concrete Piles ◽  
Test Methodology ◽  
Ground Conditions ◽  
Load Tests

In this paper the analysis results of precast piles different tests are presented. Extreme soil conditions of Astana (Kazakhstan) involve realizing the work precast piles in various soil ground and interaction soil ground and piles. There were carried out dynamic and static load tests of piles in extreme soil ground conditions in Astana. Based on data results of pile foundations the piles bearing capacity was determined. According to the results of DLT with PDA of driving piles (30.0 cm) the bearing capacity of the piles is 911 kN. The bearing capacity of the driven piles according to the results of SLT amounted to be 878 kN. Soils physic-mechanical properties in extreme conditions of Astana along with graphs of dependence are between settlement and load. The precise analysis of climatic and geological factors of the construction sites is shown. Investigations method for precast concrete piles testing is presented. Dynamic load test methodology in Astana for concrete piles testing is shown.  These investigations are important for of Pile-Soil interaction on problematical soil ground.

scholarly journals Improving The Prediction For The Ultimate Axial Capacity Of Driven Piles In Ontario Soils With A Genetic Algorithm

2021 ◽  
Author(s):  
Markus Jesswein
Keyword(s):  
Genetic Algorithm ◽  
Influential Factors ◽  
Design Methods ◽  
Driven Piles ◽  
Compression Load ◽  
Axial Capacity ◽  
Side Resistance ◽  
Ground Conditions ◽  
Load Tests ◽  
Soil Measurements

A genetic algorithm (GA) was developed to improve predictions for the ultimate axial capacity of driven piles in Ontario soils. Challenges arise to accurately predict the ultimate capacity due to many influential factors, such as the ground conditions, installation method, and pile geometry. A total of 43 piles (H or pipe piles) were collected from the Ministry of Transportation of Ontario. Side and tip resistances were extracted from piles subjected to extension and compression load tests. The soil measurements and pile resistances were regressed with a statistical analysis and GA, and the developed relationships were compared to existing design methods. On average, existing design methods overestimated the capacity by a factor of 1.16 to 3.00. The proposed correlations were slightly conservative with the capacity but provided errors within ± 30 % of the measured side resistance. The new design methods from the GA offer substantial improvements for pile design

Sign in / Sign up

Export Citation Format

Share Document