Download or read book Improving Design Phase Evaluations of High Pile Rebound Soils with an Emphasis on SPT Testing written by and published by . This book was released on 2019 with total page 159 pages. Available in PDF, EPUB and Kindle. Book excerpt: Florida Institute of Technology researchers investigated the use of standard geotechnical tests to determine areas prone to high pile rebound (HPR). Test results were used in conjuntion with a decision tree the researchers had developed in a previous project.

Download or read book Improving Design Phase Evaluations for High Pile Rebound Sites Final Report written by and published by . This book was released on 2016 with total page 459 pages. Available in PDF, EPUB and Kindle. Book excerpt: A testing program performed to help determine typical soils properties encountered during pile installation when high rebound occurs produced a decision matrix for geotechnical engineers. High pile rebound (HPR) occurred at numerous sites in Florida. Samples from standard penetration test (SPT) borings and thin-walled tube sample borings were used in addition to cone penetrometer with pore pressure (CPTu) data to determine soil properties trends.

Download or read book Evaluating Geotechnical Engineering Properties Associated with High Pile Rebound written by Fauzi H. M. Jarushi and published by . This book was released on 2013 with total page 1078 pages. Available in PDF, EPUB and Kindle. Book excerpt: At certain depths during driving of large diameter displacement piles, rebound greater than 0.25 inches occurs, followed by a small permanent-set after each hammer blow. This phenomenon is called high pile rebound (HPR). HPR soils may stop the pile driving and result in a limited pile capacity. The overburden depth at which HPR occurs is typically greater than 50 ft. In some cases, rebound leads to pile damage, delaying of the construction project and foundations redesign. The objective of this research was to develop a geotechnical engineering protocol that would allow the geotechnical engineer to identify soil properties and strata which might cause HPR before pile driving begins (i.e., during the design phase of the project). A total of 172 test piles at 138 pier locations, including 102 large prestressed concrete piles (PCP) and 70 low displacement steel H-Piles, were evaluated so as to select the HPR sites where geotechnical data could be collected. Based on available geotechnical data, 21 PCP piles at eleven sites were chosen for this investigation. The H-piles did not experience any HPR problems and thus were not studied. All HPR piles were driven into saturated, fine silty to clayey sands and sandy clays or fat clays. A complete subsurface investigation was conducted after all HPR piles were installed. It included Standard Penetration Testing (SPT), retrieval of disturbed samples, lab testing to produce basic geotechnical index properties, plus Cone Penetrometer Testing (CPT) with pore water pressure measurements. A total of 43 SPT test borings and 27 CPT soundings were performed and evaluated. Pile Driving Analyzer (PDA) data from all the test piles was reduced to a deflection versus time to enable both the maximum and final displacements per blow to be used in calculating rebound. Maximum displacement and inspector set (iSet), recorded during installation of the test piles, was used to develop several promising correlations between pile rebound, or inspector set and SPT blow counts (NSPT), fines content, and CPT. In soil conditions where the NSPT values were 15 blows/ft or less with a fines content of 25 percent (i.e., analyses include 21 piles at eleven sites), the rebound was less then 0.25 inches and yielded an acceptable pile permanent-iSet of up to 3 inches. When the NSPT values were between 15 and 40 blows/ft with a fines content of 25 to 40 percent, the pile rebound varied between 0.25 and 0.6 inches but still produced an acceptable permanent-iSet. As the NSPT exceeded 40 blows/ft with a fines content greater than 40 percent, the pile rebound was greater than 0.6 inch accompanied by a small or zero (i.e., unacceptable) permanent i-Set. Where piles experienced excessive HPR with zero or minimal permanent-iSet at 8 piles, the CPTu pore water pressure (u2) yielded very high positive values of more than 20 tsf. However, at the two sites (i.e., 4 piles) where the pile rebounded, and was followed by an acceptable permanent-iSet, the measured CPTu u2 ranged between 5 and 20 tsf, the u2 exhibited values of less than 5 tsf at two piles where no rebound detected. Direct linear correlations between CPTu u2 and rebound were produced with strong linear correlations with regression coefficients R2 of 0.6 or higher. In these cases, the permanent-iSet decreased and rebound increased as u2 increased. Rebound versus u2 or u2/hydrostatic pressure (u0) pressure produced a linear plot through the origin, indicating rebound would equal approximately 2.5% of the CPTu u2 or 5.5% of the u2/u0. Therefore, these correlations between CPTu pore pressure and rebound allow identification of soils that produce HPR. In order to improve the knowledge about the soil types producing HPR, Piezocone data at HPR sites were interpreted using CPT and CPTu soil behavior type (SBT) charts developed by 1) Schmertmann (1978), 2) Eslami and Fellenius (2004), 3) Robertson (1990), and 4) Schneider et al. (2008). SBT charts allow geotechnical engineers to fully utilize the behavior of HPR soils. HPR soils are classified as dense or stiff by Schmertmann (1978); and categorized as silty sand or silty clay to clay silt by the Eslami-Fellenius (2004) chart, where [CPT sleeve friction] is greater then 0.80 tsf and [CPT Cone resistance] is greater than 200 tsf. The Robertson (1990) SBT chart showed that most HPR soils were in zone 4 (i.e., clayey silty to silty clay), with a [pore pressure] ratio of greater than 0.4 and a friction ratio of greater than 1.5%. Most non-HPR soils on these charts were in zone 6 (clean sand to silty sand). The most promising chart was developed by Schneider et al. (2008), and classified HPR layers as 1a and 1b (silt and clays) with [excess pore pressure] of greater than 1, while non-HPR soils were plotted in transitional soils, zone 3 (sand), with [excess pore pressure] of less than 1. Comparison of these results with classifications from laboratory tests were in excellent agreement with CPT soil type, and therefore the CPT can be a useful tool in evaluation of HPR soils. Statistical analyses were performed on the geotechnical data using SPSS software (Statistical Package for Social Sciences). Equations and a nomograph to predict pile rebound were developed which then were investigated for the adequacy of fit. An analysis of variance (ANOVA) was conducted to determine if there was any significant relationship between rebound, NSPT and fines content or friction ratio and CPTu pore pressure. The applicability of equations and the nomograph was evaluated by plotting the predicted rebound versus actual rebound. The actual rebound data was from sites which were not used to develop the equations and the nomograph. The performance of both the equation and the design chart produced R2 values of 0.70 or higher. Statistical logistic regression modeling was also carried out on the geotechnical data using SPSS software. As a result, the models showed that the probabilities of HPR increased as either the fines content or NSPT increased and the regression coefficient R2 approached 1.0. The probability of the HPR was greater than 50 percent when the NSPT exceeded 30 blows/ft and the fines content exceeded 35 percent. The probability of HPR using CPTu pore pressure was greater than 50 percent when the pore pressure was greater than 16 tsf. The relationship between HPR and CPTu pore pressure produced a strong correlation coefficient of R2 approaching 1.0. The statistical logistic regression modeling and equations showed promise in predicting rebound. This methodology may lead to a simpler evaluation process which allows engineers to predict HPR during the design phase. A variety of methods were shown to be effective in predicting HPR and the correlations developed in this study allow the geotechnical engineer to predict if HPR will occur at a proposed site, where high displacement piles are to be driven using a single-acting diesel hammer. The correlations showed that permanent-iSet and rebound were a direct function of NSPT and fines content or friction ratio R[f] and pore pressure u2 of the soil at the pile tip. The design equations and corresponding nomograph developed provide a methodology that allows for the prediction of HPR during the design phase.

Download or read book Engineering Properties of Pile Rebound Soils Based on Cone Penetration Testing written by Hadeel Dekhn and published by . This book was released on 2015 with total page 416 pages. Available in PDF, EPUB and Kindle. Book excerpt: High pile rebound (HPR) has been identified by Florida Department of Transportation (FDOT) to occur during the installation of square prestressed concrete piles at many sites in Florida. Significant pile rebound values of up to 1.5 inch/blow were measured resulting in increased blow counts. Pile refusal is a common occurrence when blow count exceeds 240 blow/ft; leading to pile redesign and economic consequences. The overall objective of this research is to identify the engineering properties of soil deposits which may cause HPR and develop improved correlations that may be used to predict HPR during the design process. Seven sites were studied in this research. Pile driving analyzer (PDA) data was used to identify the rebound zones. Cone penetration tests (CPT) and Standard penetration tests (SPT) were conducted near the associated test piles. The SPT data was used to develop soil profile for each site. The CPT data was used to estimate profiles of engineering soil properties. An existing correlation between the CPT pore pressure and pile rebound was evaluated and improved. High CPT pore pressures measured at the rebound zones were found to correlate linearly with pile rebound. Using the CPT the rebound soils were classified as dense silty sands and highly overconsolidated or cemented silty clays. These soils are dilative under shear loading increasing the shear strength of the surrounding soil and the pile skin friction. As a result higher blow counts are required to reach pile penetration. The HPR soils have very low permeability; therefore, high compression-induced pore pressures may be generated near the pile tip during driving. These pore pressures at the pile tip may provide upward forces leading to rebound. The SPT data showed that cemented silty fine sand (SM) and clayey fine sand (SC) with trace phosphate and shell with fines content of 25 % to 40 % were found in the rebound zones. The CPT data superimposed on soil behavior type (SBT) charts provides an engineering method to predict pile rebound soils.

Download or read book Design Phase Identification of High Pile Rebound Soils written by Paul J. Cosentino and published by . This book was released on 2010 with total page 140 pages. Available in PDF, EPUB and Kindle. Book excerpt: The objective of this research was to determine geotechnical testing protocol that would help engineers anticipate high rebound. The literature review revealed high pile rebound sites throughout North America. This problem typically occurred when displacement piles were driven into medium dense or stiff saturated silts and clays, using single acting hammers. An extensive laboratory and field testing program was conducted at three existing FDOT project sites. Two were located in the Orlando area and the third in the Florida Panhandle. The field testing included Standard Penetration Borings with N-values; Pocket Penetrometer unconfined compressive tests; Cone Penetrometer soundings that produced point bearing; sleeve friction and pore water pressures; PENCEL Pressuremeter tests that produced in situ stress-strain data; and Dilatometer soundings to produce lift-off pressures and elastic moduli.

Download or read book Reevaluating Engineering Properties of Pile Rebound Soils Based on Standard Penetration Testing written by Brian Frederick Wisnom and published by . This book was released on 2015 with total page 664 pages. Available in PDF, EPUB and Kindle. Book excerpt: Pile rebound has been identified by Florida Department of Transportation (FDOT) to occur during the installation of square prestressed concrete piles. High Pile Rebound (HPR) has been identified from Brevard County to the panhandle. At times observed up to 3 inches, rebound and HPR result in excessive blow counts, an increased potential for damaged piles, early refusal conditions, decreased capacities, and even pile redesigns during construction. The objective of this research was to verify correlations developed by Cosentino, Kalajian, and Jarushi (2011) and Jarushi (2013), who previously identified uncorrected Standard Penetration Test (SPT) blow counts and soil fines content (FC) as pile rebound indicators. Both proposed that denser sand and harder clay soils, along with higher FC's that result in high excess pore water pressures, would resist permanent pile set and result in HPR. Eleven sites and twenty-five test piles were reviewed as part of this research. Raw PDA files were manipulated to identify rebound which was then correlated to safety hammer equivalent SPT N blow counts (Nsafe). Common empirical SPT correlations, relating N to the engineering properties of soil deposits, and soil relationships with respect to liquefaction potential were reviewed. Maximum rebound was found to occur when Nsafe was less than 20 blows per foot, and generally decreased as Nsafe increased, though SPT refusal conditions did produce excessive rebound in silty and clayey sands. In addition, it was found that rebound magnitudes were influenced by the presence of fines up to a FC of 40%, at which any further increase in fines produced less rebound. These findings did not match or verify the proposed correlations by Cosentino et al. (2011) and Jarushi (2013). Additional soil engineering properties were reviewed, but it became apparent that direct review of SPT and rebound data did not account for all variables as it only considered conditions beneath the pile toe. Review of PDA total skin friction (SFT) found that maximum pile rebound only occurred when SFT resistances were negligible. As SFT increased, the corresponding rebound decreased, and excessive SFT resulted in negligible rebound for all soils. In addition, laboratory testing results on post construction SPT borings, and pile rebound identified within test pile driving logs were reviewed together. Though the analysis was limited to only four test piles, it showed that liquefaction resistant soils were present when rebound occurred.

Download or read book Pile Design and Construction Practice written by Willis H. Thomas and published by CRC Press. This book was released on 2007-12-06 with total page 566 pages. Available in PDF, EPUB and Kindle. Book excerpt: This international handbook is essential for geotechnical engineers and engineering geologists responsible for designing and constructing piled foundations. It explains general principles and practice and details current types of pile, piling equipment and methods. It includes calculations of the resistance of piles to compressive loads, pile group

Download or read book Contemporary Topics in Deep Foundations written by Magued Iskander and published by . This book was released on 2009 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: GSP 185 contains 80 papers presented at the International Foundation Congress and Equipment Expo held in Orlando, Florida, March 15-19, 2009.

Download or read book Principles and Practice of Ground Improvement written by Jie Han and published by John Wiley & Sons. This book was released on 2015-06-22 with total page 432 pages. Available in PDF, EPUB and Kindle. Book excerpt: Gain a stronger foundation with optimal ground improvement Before you break ground on a new structure, you need to analyze the structure of the ground. Expert analysis and optimization of the geo-materials on your site can mean the difference between a lasting structure and a school in a sinkhole. Sometimes problematic geology is expected because of the location, but other times it's only unearthed once construction has begun. You need to be able to quickly adapt your project plan to include an improvement to unfavorable ground before the project can safely continue. Principles and Practice of Ground Improvement is the only comprehensive, up-to-date compendium of solutions to this critical aspect of civil engineering. Dr. Jie Han, registered Professional Engineer and preeminent voice in geotechnical engineering, is the ultimate guide to the methods and best practices of ground improvement. Han walks you through various ground improvement solutions and provides theoretical and practical advice for determining which technique fits each situation. Follow examples to find solutions to complex problems Complete homework problems to tackle issues that present themselves in the field Study design procedures for each technique to simplify field implementation Brush up on modern ground improvement technologies to keep abreast of all available options Principles and Practice of Ground Improvement can be used as a textbook, and includes Powerpoint slides for instructors. It's also a handy field reference for contractors and installers who actually implement plans. There are many ground improvement solutions out there, but there is no single right answer to every situation. Principles and Practice of Ground Improvement will give you the information you need to analyze the problem, then design and implement the best possible solution.

Download or read book Handbook of Geotechnical Investigation and Design Tables written by Burt G. Look and published by CRC Press. This book was released on 2007-04-26 with total page 356 pages. Available in PDF, EPUB and Kindle. Book excerpt: This practical handbook of properties for soils and rock contains, in a concise tabular format, the key issues relevant to geotechnical investigations, assessments and designs in common practice. In addition, there are brief notes on the application of the tables. These data tables are compiled for experienced geotechnical professionals who require a reference document to access key information. There is an extensive database of correlations for different applications. The book should provide a useful bridge between soil and rock mechanics theory and its application to practical engineering solutions. The initial chapters deal with the planning of the geotechnical investigation, the classification of the soil and rock properties and some of the more used testing is then covered. Later chapters show the reliability and correlations that are used to convert that data in the interpretative and assessment phase of the project. The final chapters apply some of these concepts to geotechnical design. This book is intended primarily for practicing geotechnical engineers working in investigation, assessment and design, but should provide a useful supplement for postgraduate courses.

Download or read book Geo frontiers 2011 written by and published by . This book was released on 2011 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Evaluation of Soil and Rock Properties written by P. J. Sabatini and published by . This book was released on 2004-10-01 with total page 392 pages. Available in PDF, EPUB and Kindle. Book excerpt: This document presents state-of-the-practice information on the evaluation of soil and rock properties for geotechnical design applications. This document addresses the entire range of materials potentially encountered in highway engineering practice, from soft clay to intact rock and variations of materials that fall between these two extremes. Information is presented on parameters measured, evaluation of data quality, and interpretation of properties for conventional soil and rock laboratory testing, as well as in situ devices such as field vane testing, cone penetration testing, dilatometer, pressuremeter, and borehole jack. This document provides the design engineer with information that can be used to develop a rationale for accepting or rejecting data and for resolving inconsistencies between data provided by different laboratories and field tests. This document also includes information on: (1) the use of Geographical Information Systems (GIS) and Personal Data Assistance devices for the collection and interpretation of subsurface information; (2) quantitative measures for evaluating disturbance of laboratory soil samples; and (3) the use of measurements from geophysical testing techniques to obtain information on the modulus of soil. Also included are chapters on evaluating properties of special soil materials (e.g., loess, cemented sands, peats and organic soils, etc.) and the use of statistical information in evaluating anomalous data and obtaining design values for soil and rock properties. An appendix of three detailed soil and rock property selection examples is provided which illustrate the application of the methods described in the document.

Download or read book Engineering Geology Field Manual written by and published by . This book was released on 1998 with total page 510 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Basics of Foundation Design written by Bengt Fellenius and published by Lulu.com. This book was released on 2017-03-17 with total page 488 pages. Available in PDF, EPUB and Kindle. Book excerpt: The "Red Book" presents a background to conventional foundation analysis and design. The text is not intended to replace the much more comprehensive 'standard' textbooks, but rather to support and augment these in a few important areas, supplying methods applicable to practical cases handled daily by practising engineers and providing the basic soil mechanics background to those methods. It concentrates on the static design for stationary foundation conditions. Although the topic is far from exhaustively treated, it does intend to present most of the basic material needed for a practising engineer involved in routine geotechnical design, as well as provide the tools for an engineering student to approach and solve common geotechnical design problems.

Download or read book Foundation Design Principles and Practices written by Donald P. Coduto and published by Pearson Higher Ed. This book was released on 2013-10-03 with total page 889 pages. Available in PDF, EPUB and Kindle. Book excerpt: For undergraduate/graduate-level foundation engineering courses. Covers the subject matter thoroughly and systematically, while being easy to read. Emphasizes a thorough understanding of concepts and terms before proceeding with analysis and design, and carefully integrates the principles of foundation engineering with their application to practical design problems.

Download or read book Design of Pile Foundations written by Aleksandar Sedmak Vesić and published by Transportation Research Board. This book was released on 1977-01-01 with total page 68 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Cone Penetration Testing written by Paul W. Mayne and published by Transportation Research Board. This book was released on 2007 with total page 126 pages. Available in PDF, EPUB and Kindle. Book excerpt: NCHRP synthesis 368 explores the current practices of departments of transportation associated with cone penetration testing (CPT). The report examines cone penetrometer equipment options; field testing procedures; CPT data presentation and geostratigraphic profiling; CPT evaluation of soil engineering parameters and properties; CPT for deep foundations, pilings, shallow foundations, and embankments; and CPT use in ground modifications and difficult ground conditions.