Download or read book Characterization of t z Model Design Parameters for Augered Cast in place Piles Using Field Load Test Data written by Bradley Scott Gardner and published by . This book was released on 2012 with total page 196 pages. Available in PDF, EPUB and Kindle. Book excerpt: With the increasing use of augered cast-in-place piles in new construction, it is important that proper design parameters be incorporated when evaluating pile capacity and performance using reliability-based design methods. This paper focuses on developing "t-z" model parameters from analysis of static axial compression and tension load test data from a project site along the Missouri River floodplain in northwest Missouri. Data was collected from a total of twelve axial load tests (six compression and six tension) and includes dial gauge readings from the pile heads as well as vibrating wire strain gauge data from multiple locations throughout several of the test piles. The "t-z" method has been used extensively as a soil-structure interaction model to evaluate the settlement of deep foundations. The soil-structure interaction modeled in this analysis was based on hyperbolic load displacement behavior using effective (drained) stresses. The development of the "t-z" model parameters has been accomplished using finite difference methods to analyze the non-linear soil-structure interaction along the sides of the piles. During the analysis, the mean shear modulus of soil-structure interface subgrade reaction, K[sub]init, and the mean ultimate shear strength of the soil-structure interface, [symbol for tau][sub]u, were back-calculated from each set of load test data and were based on the assumption of a single-layer, homogenous soil profile. These "t-z" model parameters were then compared to standard field investigation data, including standard penetration tests (SPT) and cone penetrometer test (CPT) soundings, and effective overburden stress to develop correlations suitable for service limit state design of augered cast-in-place piles. While there was some indication of a linear relationship between K[sub]init and the field investigation data, there was not a sufficient quantity of data in the analysis to properly identify any statistical trends. The relationship between [symbol for tau][sub]u and the field investigation data was much more variable and did not provide any distinct correlation. The plot of the data relating the model parameters to the effective overburden stress exhibited some grouping but the sample size and distribution was not sufficient to identify any statistical trends.

Download or read book Design and Construction of Auger Cast Piles and Other Foundation Issues written by and published by . This book was released on 1994 with total page 140 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Comparison of Load Test Data and Predicted Behavior of Auger Cast Piles in Layered Soils written by John Michael Hudson and published by . This book was released on 2008 with total page 173 pages. Available in PDF, EPUB and Kindle. Book excerpt: The use of auger cast-in-place (ACIP) pilings is very common in Florida; however, there is a significant degree of uncertainty in determining the actual capacity of the pilings, especially when the pilings are installed through layers of cohesive soils. Therefore, there is a need to improve upon the existing methods of predicting the behavior of ACIP piles in layered soils. As a result, the primary objective of this study is to determine if a significant difference exists between the accepted methods of pile load test analysis. Provided a significant difference is noted, the secondary objective would be to determine if an improvement could be made to enhance the existing empirical relationships used to predict pile behavior in layered soils. In order to accomplish these objectives, this study presents an evaluation of some of the most commonly used methods for predicting ACIP pile capacity based upon the results of actual field load tests. Data from twenty-five load tests were analyzed using popular methods and statistical analyses were preformed to determine and evaluate the data. These evaluations were utilized to explore correlations between predicted behavior and actual results. Based upon the results of this study, there is no statistically significant difference between the load test analyses methods examined. As a result, no improvement to the existing methods of predicting ACIP pile behavior in layered soils may be recommended at this time, and further research in this subject matter is recommended.

Download or read book Load Transfer Criteria for Numerical Analysis of Axially Loaded Piles in Sand Part 1 Load Transfer Criteria written by R. L. Mosher and published by . This book was released on 1984 with total page 390 pages. Available in PDF, EPUB and Kindle. Book excerpt: Part I describes a study of load-transfer criteria for analysis of axially loaded piles in sand using the discrete springs soil model. Various analysis methods for axially loaded piles are presented, along with a literature review of pile behavior in sands focusing on the changes the soil undergoes during pile installation. Available criteria for spring representation of soil are presented and summarized. The criteria are compated with actual field data from pile load tests and are critically evaluated based on these comparisons. Because of the poor performance of the available criteria, new criteria are proposed. The new criteria use maximum side and tip resistance values presented by Castello (1980). Castello's values are modified by the author to reflect the field data from the Lower Mississippi Valley. Displacement functions for side and tip resistance are developed based on correlations with field data for pile load tests. The new criteria are evaluated against pile load test data. Use of the critieria is demonstrated in an outline of an analysis. The new criteria are used to develop a set of design curves for the practicing engineer. Part II of this report is published under a separate cover, and presents load capacity curves for select steel and concrete pile.

Download or read book Modeling Load Transfer Behavior of H Piles Using Direct Shear and Penetration Test Results written by Sherif S. AbdelSalam and published by . This book was released on 2014 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt: The load transfer analysis (or t-z analysis) has long been used to predict the load-displacement response of axially loaded driven piles. However, the t-z curves along the pile length and q-z curve at the pile tip, required for the t-z analysis, are routinely obtained based on empirical correlations using field and/or laboratory soil tests. This study focuses on the use of a modified Direct Shear Laboratory Test (mDST) to directly quantify the t-z curves and the use of a penetration test, namely the Pile Tip Resistance test (PTR) to quantify the q-z curve, for partial-displacement piles. As part of this study, two instrumented steel H-piles driven in sandy soils were load tested and soil layers at the two sites were characterized using in situ and laboratory tests. A load transfer analysis was conducted utilizing the directly quantified t-z and q-z curves from the mDST and PTR, respectively, to calculate the response of the load tested piles. When compared to the measured load-displacement response and load distribution along pile length, the t-z analysis based on the mDST and PTR measurements showed very good agreement with the measured pile responses. Therefore, and despite the limited database availability at present, the proposed mDST-PTR based model is promising as it represents a simple and cost-effective means to accurately predict the load-displacement response of partial-displacement piles driven in cohesionless soils.

Download or read book Recommendations on Piling EA Pf hle written by Geotechnik and published by John Wiley & Sons. This book was released on 2013-12-09 with total page 496 pages. Available in PDF, EPUB and Kindle. Book excerpt: This handbook provides a complete and detailed overview of piling systems and their application. The design and construction of piled foundations is based on Eurocode 7 and DIN 1054 edition 2010 as well as the European construction codes DIN EN 1536 (Bored piles), DIN EN 12699 (Displacement piles) and DIN EN 14199 (Micropiles). These recommendations also deal with - categorisation of piling systems, - actions on piles from structural loading, negative skin friction and side pressure, - pile resistances from static and dynamic pile test loading as well as extensive tables with the pile load-bearing capacity of nearly all piling systems based on values from practical experience, - pile groups, - performance of static and dynamic test loading and integrity tests, - load-bearing behaviour and verifications for piles under cyclical, dynamic and impact actions - quality assurance for construction. An appendix with numerous calculation examples completes the work. As part of the approval procedure for offshore wind energy structures, the Federal Office for Shipping and Hydrography (BSH) demands verifications according to the new Chapter 13 ("Load-bearing behaviour and verifications for piles under cyclical, dynamical and impact actions") of the EA Pfähle (the recommendations of the Piling working group - 2nd edition), which deals with external pile resistance for the foundations of offshore wind energy structures and the types of verifications to be provided under cyclical actions. The publication of the EA-Pfähle recommendations by the Piling working group of the German Society for Geotechnics (DGGT), which works with the same members as the piling standards committee NA 00-05-07, is intended to provide assistance for engineers active in the design, calculation and construction of piled foundations. The recommendations can thus be considered as rules of the technology and as a supplement to the available codes and standards.

Download or read book Rapid Load Testing on Piles written by Paul Holscher and published by CRC Press. This book was released on 2008-08-28 with total page 200 pages. Available in PDF, EPUB and Kindle. Book excerpt: To obtain data about the stiffness and bearing capacity of a foundation pile, the Rapid Load Test could be an effective and economic alternative for a static load test. In order to judge this, the influence of rate effects in clay and pore water pressures in sand should first be understood. This book presents the latest developments in the research

Download or read book Deep Foundations on Bored and Auger Piles BAP III written by W. Haegeman and published by CRC Press. This book was released on 2020-09-29 with total page 1063 pages. Available in PDF, EPUB and Kindle. Book excerpt: This text presents findings from the 3rd International Geotechnical Seminar, held in Ghent, Belgium. Topics include: American experiences with large diameter bored piles; case histories; static, dynamic and pile integrity testing; and installation parameters and capacity of screwed piles.

Download or read book Case History Evaluation of Axial Behavior of Augered cast in place Piles and Pressure injected Footings written by Jie-Ru Chen and published by . This book was released on 1998 with total page 872 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Pile Load Tests to Evaluate Load Transfer Mechanisms written by MW. Montgomery and published by . This book was released on 1979 with total page 13 pages. Available in PDF, EPUB and Kindle. Book excerpt: Load transfer mechanisms in 17 test piles are evaluated by means of an extensive monitoring program during full-scale load testing and are compared with behavior computed by a displacement compatibility analysis. H-piles, Raymond step taper piles, auger-cast piles, and steel pipe piles were tested, in many cases to failure. These piles were installed at a power generating station in saprolites of the Piedmont Province of Georgia. Deflection was measured at the butt of each pile and at the tip and one or two intermediate levels in most piles by means of telltales. A boring and laboratory testing program was an integral part of the program. Load transfer mechanisms are evaluated by means of a displacement compatibility analysis using results of the field and laboratory investigations. Good agreement between computed pile behavior and that determined by the monitoring program during load testing is demonstrated. The results of the monitoring program and the enhanced understanding of the load transfer mechanisms involved make a comparison of the effectiveness of the various pile types possible and allow development of rational installation criteria.

Download or read book Development of an ACIP Pile specific Load displacement Model written by Nasim Adami and published by . This book was released on 2013 with total page 154 pages. Available in PDF, EPUB and Kindle. Book excerpt: Augered cast-in-place piles, also known as ACIP piles, have been used for more than seven decades in the United States and have gained in popularity due to their relatively quick installation and cost-effectiveness. Owing to the reduced impact on the neighboring environment as compared to some other deep foundation installation methods, ACIP piles are appropriate for use in urban areas. Although there has been an increase in application of ACIP piles, relatively little research on this type of pile has been performed as compared to similar deep foundations, such as drilled shafts. The insufficient experimental work on ACIP pile behavior and lack of ACIP pile specific load- displacement models have led practicing engineers to use the results and methodologies from drilled shafts. An example of this is the use of t-z and q-z based load transfer models from drilled shaft-specific relationships to estimate the load-displacement behavior of ACIP piles. Such applications can result in an underestimation of shaft resistance and consequently disagreement between the predicted and measured load-displacement behavior of the ACIP piles. This thesis evaluates the ability of currently used load-displacement models to estimate the measured load-displacement behavior of ACIP piles. Also, a new empirically-based ACIP pile-specific t-z model is proposed that, in combination with the O'Neill and Reese (1999) q-z model and ACIP pile-specific toe bearing resistance model, forms an ACIP pile specific load-displacement model. Experiments of instrumented ACIP piles installed in the granular soils of Western Washington were used to develop the ACIP pile specific t-z model. Comparison between the results from the currently used load-displacement models with the proposed model showed that the proposed model provides an improvement in the prediction of the load-displacement behavior of ACIP piles. Finally, an analysis of variability is performed using the Monte Carlo Simulation with the sample probability distributions of the uncertain variables in load-displacement model. These analyses result in provide a set of possible loads for a number of common service level displacements, which are reported as cumulative density function (CDF) curves. The CDF curves for loads corresponding to a displacement considered can be a useful tool in design procedure of ACIP piles.

Download or read book Design of Axially Loaded Piles European Practice written by F. De Cock and published by CRC Press. This book was released on 2020-12-17 with total page 394 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is unique on the subject because it is not so much a collection of individual work, but basically comprising national reports from most European countries on the present-day design methods, as prescribed in more or less strict national codes or recommendations and so daily used in practice by consulting engineers and contractors. As far as already implemented, the application of these methods within the framework of Eurocode 7 is described as well. In order to improve the understanding of the design methods, the national papers also consider aspects such as the local piling practice, limitations of the design methods, some practical examples and particular national experiences. The proceedings also include the contributions of two invited speakers as well as those of the three session discussion leaders, focusing on some particular aspects with regards to pile design. The book is of particular interest for those who are involved with pile design in practice, consulting engineers, piling contractors, control organisms as well as those dealing with geotechnical normalisation and research work.

Download or read book Empirical Relationships Between Load Test Data and Predicted Compression Capacity of Augered Cast in place Piles in Predominantly Cohesionless Soils written by Donald Jeffery McCarthy and published by . This book was released on 2008 with total page 209 pages. Available in PDF, EPUB and Kindle. Book excerpt: Augered Cast-In-Place (ACIP) Piles are used in areas were the loading from a superstructure exceeds the soil bearing capacity for usage of a shallow foundation. In Northwest Florida and along the Gulf Coast, ACIP piles are often utilized as foundation alternatives for multi-story condominium projects. Data from 25 compression load tests at 13 different project sites in Florida and Alabama were analyzed to determine their individual relationships between anticipated and determined compression load capacity. The anticipated capacity of the ACIP pile is routinely overestimated due to uncertainties involved with the process of estimating the compressive capacity and procedures of placing the piles; therefore, larger diameter and deeper piles are often used to offset this lack of understanding. The findings established in this study will provide a better empirical relationship between predicted behaviors and actual behaviors of ACIP piles in cohesionless soils. These conclusions will provide the engineer with a better understanding of ACIP pile behaviors and provide a more feasible approach to more accurately determine the pile-soil interaction in mostly cohesionless soils.

Download or read book Enhanced Load Transfer Analysis for Friction Piles Using a Modified Borehole Shear Test written by Sherif S. AbdelSalam and published by . This book was released on 2012 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt: This study discusses the development and use of a modified borehole shear test (mBST) to improve the prediction of the load-displacement and load-distribution responses for axially loaded friction piles in cohesive soils using the load-transfer analysis method (i.e., t-z analysis). Unlike available approaches that rely on empirical or semi-empirical correlations to generate the shear stress displacement at the soil-pile interface (i.e., t-z curves), the mBST enables direct field measurement of the t-z curves at the soil-pile interface. As part of this study, three full-scale vertical static load tests (SLTs) were conducted on instrumented steel H piles. The t-z analysis was carried out utilizing the TZPILE software with measured t-z curves via the mBST (i.e., the TZ-mBST model). When comparing results of the analysis with the measured responses for the three test piles, it was found that: (1) the TZ-mBST provides proper prediction for the initial part of the measured load-displacement response from SLT results, with a difference not exceeding 10 %; (2) the TZ-mBST analysis provides acceptable prediction of the pile capacity; (3) the TZ-mBST analysis matches the load distribution along the pile length with a maximum difference of 8.3 %; and (4) the analysis with directly measured t-z curves using the mBST provide improved predictions of the pile response when compared to the empirical CPT-based analysis.

Download or read book Determination of P y Curves by Direct Use of Cone Penetration Test CPT Data written by SHAWN SHAHRIAR ARIANNIA and published by . This book was released on 2015 with total page 249 pages. Available in PDF, EPUB and Kindle. Book excerpt: The current best practice in geotechnical engineering in determining lateral capacity of piles is to replace the soil reaction with a series of independent springs. Basically, the model uses beam theory to represent the pile and uncoupled, non-linear load transfer functions, called p-y curves to represent the soil. Most of the existing methods for determining p-y curves are highly empirical, based on a limited number of cases of laterally loaded piles, which were instrumented, enabling to measure the pile deflection in discrete depth intervals subject to different lateral load (i.e. Matlock 1970, Reese 1975). In essence, these methods have their own limitations, and are mainly applicable for the conditions similar to the tested conditions. Although later, more detailed investigations by different people addressed some of the problems, still the basis of the existing design programs such as LPILE, or procedures introduced in applicable codes such as API (American Petroleum Institute), is the same original recommendations made by Matlock and Reese during seventies. In recent era, demand in employment of in-situ direct-pushed based methods using multi-measurement in-situ devices, such as the seismic cone penetration test with pore water measurement (SCPTu) and Seismic Flat Dilatometer Test (SDMT) is significantly increased. The main objective of this research is to introduce a unified CPT-based approach for determining p-y curves and pile responses to lateral loads. The suggested approach will provide explicit and defined steps/criteria to develop p-y curves for piles subjected to lateral loads using CPT data. CPT data will be used to determine soil strength parameters. Recent developments in relating CPT data to soil basic parameters using Critical State Soil Mechanics (CSSM) framework will be implemented in the suggested model. In all current common models, pre-determination of the soil behavior and the model to be used (e.g. Matlock clay, 1970 or Reese sand, 1975), will become warranted even before commencement of the analysis. On the contrary, in the proposed model, the need for the said pre-determination of soil behavior is eliminated. As discussed in Section 2.3.5, soil behavior in the model is being classified into four broad and general groups: drained-dilative, drained- contractive, undrained-dilative and undrained-contractive The main factor driving the suggested analytical approach is Soil Behavior Type Index, Ic. In the proposed approach, the SBT index, Ic, will be used to determine the in-situ characteristics and behavior of the soil. Based on the value of Ic calculated from CPT data, it could be determined that the soil behaves as a sand-like or a clay-like soil, and during the shearing would behave in undrained or drained condition. The measured shear wave velocity during field test using seismic cone penetration test or other methods such as SASW (Spectral Analysis of Surface Waves) or Cross-Hole logging, may be used to determine the small strain shear modulus, G0, which corresponds to the initial stiffness of the linear part of the p-y curve. In this research, the proposed model will be verified using collected case histories of laterally loaded piles with available CPT data at the same site. The p-y curves, and pile force-head displacements determined from the model will be compared to the field-resulted p-y curves and pile head displacement measurements available from the case histories.

Download or read book Recent Experiences Advancements in the U S and Abroad on the Use of Auger Cast in place Piles written by and published by . This book was released on 2004 with total page 122 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Pile Design and Construction Practice written by Michael Tomlinson and published by CRC Press. This book was released on 2014-10-08 with total page 597 pages. Available in PDF, EPUB and Kindle. Book excerpt: Written to Eurocode 7 and the UK National AnnexUpdated to reflect the current usage of Eurocode 7, along with relevant parts of the British Standards, Pile Design and Construction Practice, Sixth Edition maintains the empirical correlations of the original-combining practical know how with scientific knowledge-and emphasizing relevant principles an