Download or read book Load and Resistance Factor Design for Driven Piles Based on Static Methods written by Thai Nguyen and published by . This book was released on 2001 with total page 304 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Load and Resistance Factor Design LRFD for Deep Foundations written by Samuel G. Paikowsky and published by Transportation Research Board. This book was released on 2004 with total page 87 pages. Available in PDF, EPUB and Kindle. Book excerpt: Introduction and research approach -- Findings -- Interpretation, appraisal, and applications -- Conclusions and suggested research -- Bibliography -- Appendixes.

Download or read book Development of Resistance Factors for Axial Capacity of Driven Piles in North Carolina written by and published by . This book was released on 2002 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Resistance factors were developed in the framework of reliability theory for the Load and Resistance Factor Design (LRFD) of driven pile's axial capacity in North Carolina utilizing pile load test data available from the North Carolina Department of Transportation. A total of 140 Pile Driving Analyzer (PDA) data and 35 static load test data were compiled and grouped into different design categories based on four pile types and two geologic regions. Resistance statistics were evaluated for each design category in terms of bias factors. Bayesian updating was employed to improve the statistics of the resistance bias factors, which were derived from a limited number of pile load test data. Load statistics presented in the current AASHTO LRFD Bridge Design Specifications were used in the reliability analysis and the calibration of the resistance factors. Reliability analysis of the current NCDOT practice of pile foundation design was performed to evaluate the level of safety and to select the target reliability indices. Resistance factor calibration was performed for the three methods of static pile capacity analysis commonly used in the NCDOT: the Vesic, the Nordlund, and the Meyerhof methods. Two types of First Order Reliability Methods (Mean Value First Order Second Moment method and Advanced First Order Second Moment method) were employed for the reliability analysis and the calibration of the resistance factors. Recommended resistance factors are presented for the three methods of static pile capacity analysis and for seven different design categories of pile types and geologic regions. The resistance factors developed and recommended from this research are specific for the pile foundation design by the three static capacity analysis methods and for the distinct soil type of the geologic regions of North Carolina. The methodology of the resistance factor calibration developed from this research can be applied to the resistance factor calibration for other foundation.

Download or read book Calibration of Resistance Factors Needed in the LRFD Design of Driven Piles written by Murad Yusuf Abu-Farsakh and published by . This book was released on 2009 with total page 126 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Load and Resistance Factor Design LRFD for Driven Piles Using Dynamic Methods A Florida Perspective written by MC. McVay and published by . This book was released on 2000 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt: The parameters for load and resistance factor design (LRFD) of driven piles using dynamic methods are presented based on a database of 218 pile cases in Florida. Eight dynamic methods were studied: ENR, modified ENR, FDOT, and Gates driving formulas, Case Analysis with Wave Analysis Program (CAPWAP), Case Method for Pile Driving Analyzer (PDA), Paikowsky's energy method, and Sakai's energy method. It was demonstrated that the modern methods based on wave mechanics, such as CAPWAP, PDA, and Paikowsky's energy methods, are roughly twice as cost effective to reach the target reliability indices of 2.0 to 2.5 (failure probability = 0.62 to 2.5%) as the ENR and modified ENR driving formulas. The Gates formula, when used separately on piles with Davisson capacities smaller or larger than 1779 kN, has an accuracy comparable to the modern methods. The utilizable measured Davisson capacity, defined as ?/? (ratio of resistance/mean capacity) obtained from testing at beginning of redrive (BOR), is only slightly larger than the end of drive (EOD) values. Furthermore, past practice with driving formulas reveals the existence of a large redundancy in pile groups against failure. The latter suggests the use of a lower relatively reliability target index, ?T = 2.0 (pf = 2.5%) for single pile design. Also, the utilizable measured Davisson capacity, ?/?, for all the dynamic methods studied, is quite similar to published values (Lai et al. 1995; Sidi 1985) for static estimates from in situ tests.

Download or read book Load and Resistance Factor Design and Construction Control of Driven Piles in Intermediate Geomaterials written by Pramila Adhikari and published by . This book was released on 2019 with total page 188 pages. Available in PDF, EPUB and Kindle. Book excerpt: Static Analysis methods originally developed for soils are currently used for estimating pile resistances in Intermediate Geomaterials (IGMs), and structural capacity has been considered as the limiting pile capacity on hard rocks. The application of current Load and Resistance Factor Design (LRFD) for piles in IGMs has resulted in relatively high uncertainties in pile resistance estimation during design and the length to which the piles are driven into IGMs during construction. Moreover, the absence of standard criteria to differentiate the geomaterials creates challenges in the design and construction of driven piles in IGMs. The application of a dynamic analysis method using Wave Equation Analysis Program is constrained by geomaterial input for IGMs and rocks. These current challenges have led to conservative pile resistance estimations. Thus, the overall objectives of this study were to determine efficient static analysis methods, dynamic procedures for construction control, pile setup/relaxation, and resistance factors for the estimation of the axial pile resistances in IGMs, ensuring a prescribed level of reliability to meet LRFD philosophy. To accomplish these objectives, classification criteria of geomaterials were first created to establish a standard quantitative delineation between the soils, IGMs, and hard rocks for the design of driven piles. In addition, a catalog of IGM properties was prepared to facilitate the preliminary design of piles in IGMs. Secondly, a new set of design equations were developed and validated for IGMs by utilizing the developed geomaterial classification criteria. Thirdly, wave equation analysis procedures for IGMs were recommended for pile construction control. Fourthly, changes in pile resistances in IGMs with respect to time at an End of Driving and Beginning of Restrike were assessed. Finally, probability based resistance factors were calibrated and recommended based on the efficiency factors for the existing and calibrated static analysis methods. Calibrated static analysis methods were concluded to have higher efficiency factors of 0.61, 0.30, and 0.41 against efficiency factors of 0.28, 0.09, and 0.14 corresponding to existing static analysis methods for shaft resistance estimation in IGMs. Similarly, calibrated static analysis methods were concluded to have higher efficiency factors of 0.24 and 0.48 against efficiency factors of 0.13 and 0.29 corresponding to existing static analysis methods for end bearing estimation in IGMs.

Download or read book New Static Analysis Methods and Improved Wave Equation Analysis Program for Driven Piles in Intermediate Geomaterials with Load and Resistance Factor Design Recommendations written by Harish Kumar Kalauni and published by . This book was released on 2021 with total page 221 pages. Available in PDF, EPUB and Kindle. Book excerpt: Accurate and reliable methods to predict resistances of driven piles in intermediate geomaterials (IGMs) are essential for improving the economics of pile design and construction.However, static analysis methods for driven piles in IGMs are rarely available. Past experiences have suggested that estimating pile resistances in IGMs using the conventional static analysis methods for soils can lead to several problems regarding pile design and construction. Thus, this study aims to develop static analysis methods and Load and Resistance Factor Design (LRFD)resistance factors to facilitate the design of driven piles in claystone, sandstone, and mudstone. Moreover, Wave Equation Analysis Program (WEAP) has been widely used to determine drivability, predict static pile resistance, and assure the integrity of piles in soils. Assigning staticand dynamic properties of IGMs remains a challenge in WEAP, partly attributed to lack of reliablemethods for unit resistance predictions for driven piles in IGMs. The challenge is further exacerbated as the recommended Smith parameters were originally developed for piles in soils.Using 129 steel H- and pipe piles driven in IGMs, improved WEAP methods and newly calibrated LRFD resistance factors are recommended. These recommendations are based on proposed static analysis methods and back-calculated Smith parameters for IGMs. An additional 46 test pile data was used to validate the recommendations. Finally, the economic impact of these WEAPrecommendations on the design and construction control of driven piles in IGMs was studied,which confirmed the economic benefits of the proposed improved WEAP methods.

Download or read book Load Resistance Factor Design LRFD for Driven Piles Based on Dynamic Methods with Assessment of Skin and Tip Resistance from PDA Signals written by Ariel Perez Perez and published by . This book was released on 1998 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: ABSTRACT: Eight dynamic methods to estimate the static capacity of driven piles were evaluated based on a Florida database and Load Resistance Factor Design (LRFD). The dynamic methods investigated were four stress wave approaches (CAPWAP, PDA, Paikowsky Energy, and Sakai Energy) and four driving formulas (ENR, modified ENR, FDOT, and Gates). In the case of the older driving formulas, the database was broken into both small (i.e. Davisson capacity less than 1779 kN) and large (Davisson capacity larger than 1779 kN) capacity piles. It was demonstrated that the modern methods based on wave mechanics, such as CAPWAP, PDA, and Paikowsky's energy method, are more accurate than the old driving formulas. The utilizable measured Davisson capacity, defined as [phi]/[lambda][subscript]R (ratio of resistance / mean capacity), shows that the new dynamic methods are more cost effective to meet a reliability index in comparison with the old methods based on momentum conservation. In addition, the Gates formula, when used separately for Davisson capacity larger than 1779 kN or less than 1779 kN, may have comparable accuracy with the modern methods. A suggested empirical method is presented to calculate the total, skin, and tip static resistance of driven piles. This method has proved to be equally or more accurate than the most widely used method (i.e. PDA, and CAPWAP). Additional features of the suggested method include determining the total, skin, and tip static capacities as the piles are being driven, saving construction time, therefore, saving construction costs.

Download or read book Load and Resistance Factor Design LRFD Pile Driving Project Phase II Study written by Aaron S. Budge and published by . This book was released on 2014 with total page 514 pages. Available in PDF, EPUB and Kindle. Book excerpt: Driven piles are the most common foundation solution used in bridge construction (Paikowsky et al., 2004). Their safe use requires to reliable verification of their capacity and integrity. Dynamic analyses of driven piles are methods attempting to obtain the static capacity of a pile, utilizing its behavior during driving. Dynamic equations (aka pile driving formulas) are the earliest and simplest forms of dynamic analyses. The development and the examination of such equation tailored for MnDOT demands is presented. In phase I of the study reported by Paikowsky et al. (2009, databases were utilized to investigate previous MnDOT (and other) dynamic formulas and use object oriented programming for linear regression to develop a new formula that was then calibrated for LRFD methodology and evaluated for its performance. This report presents the findings of phase II of the study in which a comprehensive investigation of the Phase I findings were conducted. The studies lead to the development of dynamic formulae suitable for MnDOT foundation practices, its calibrated resistance factors and its application to concrete and timber piles. Phase II of the study also expanded on related issues associated with Wave Equation analyses and static load tests, assisting the MnDOT in establishing requirements and specifications.

Download or read book Reliability based Design and Quality Control of Driven Piles written by Luo Yang and published by . This book was released on 2006 with total page 189 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Driven piles are widely used as foundations for buildings, bridges, and other structures. Since 1994, AASHTO (American Association of State Highway and Transportation Officials) has been in process to change from ASD (Allowable Stress Design) method to LRFD (Load and Resistance Factor Design) method for foundation design. The adoption of LRFD approach makes possible the application of reliability analysis to quantify uncertainties associated with various load and resistance components, respectively. Although there exist some recommendations for incorporation of set-up into ASD and quality control methods for driven piles, most of these recommendations were developed purely based on the engineering experience with no attendant database and reliability analysis. A successful application of probability approach will definitely result in significant improvements on the design and quality control of driven piles. Therefore, there is a need to develop the quality control criterion and to improve the LRFD of driven piles in the framework of reliability-based analysis. In this study, the new reliability-based quality control criteria on driven piles are developed based on acceptance-sampling analysis for various pile test methods with lognormal statistical characteristics. An optimum approach is recommended for the selection of the number of load tests and the required measured capacities for quality control of various load test methods of driven piles. The databases containing a large number of pile testing data are compiled for piles driven into clay and into sand, respectively. Based on the compiled databases, a new methodology is developed to incorporate set-up into the LRFD of drive piles using FORM (First Order Reliability Method) where the separate resistance factors for measured reference capacity and predicted set-up capacity are derived to account for different degrees of uncertainties associated with these two capacity components. Based on Bayesian theory, a new methodology is developed to optimize the LRFD of driven piles by combining the results from static calculation and dynamic pile testing. Specifically, the results from dynamic pile tests are incorporated to reduce the uncertainties associated with static analysis methods by updating the resistance factors in LRFD. Finally, a new one-dimensional wave equation based algorithm to interpret High Strain Testing data for estimation of resistances of driven piles is proposed."--abstract.

Download or read book Load and Resistance Factor Design LRFD for Analysis design of Piles Axial Capacity written by and published by . This book was released on 2002 with total page 160 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book NCHRP Report 507 written by and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Geotechnical Related Development and Implementation of Load and Resistance Factor Design LRFD Methods written by George G. Goble and published by Transportation Research Board. This book was released on 1999 with total page 80 pages. Available in PDF, EPUB and Kindle. Book excerpt: This synthesis report will be of interest to geotechnical, structural, and bridge engineers, especially those involved in the development and implementation of the geotechnical aspects of the AASHTO Bridge Code. The synthesis documents a review of geotechnical related LRFD specifications and their development worldwide to compare them with the current AASHTO LRFD Bridge Code. Design procedures for foundations, earth retaining structures, and culverts are summarized and compared with the methods specified by the AASHTO code. This TRB report provides information designed to assist engineers in implementing the geotechnical features of LRFD methods. Information for the synthesis was collected by surveying U.S. and Canadian transportation agencies and by conducting a literature search using domestic and international sources. Interviews were also conducted with selected international experts. The limited available experience in the United States and information from international practice are discussed to understand the problems that have arisen in order that solutions may be found. Based on the studies reported here, suggestions for improving the code are identified.

Download or read book Calibration of Resistance Factors for Driven Piles Using Static and Dynamic Tests written by Deshinka Arimena Bostwick and published by . This book was released on 2014 with total page 234 pages. Available in PDF, EPUB and Kindle. Book excerpt: The field of geotechnical engineering has evolved from Allowable Stress Design (ASD) to Load Factor and Resistance Design (LRFD) which has led to a need to quantify the measures of uncertainty and the level of reliability associated with a project. The measures of uncertainty are quantified by load and resistance factors, while the level of reliability is driven by the amount of risk an owner is willing to take and is quantified by the reliability index. The load factors are defined through structural design codes, but the resistance factors have uncertainties that can be mitigated through reliability based design. The American Association of State Highway and Transportation Officials (AASHTO) have recommended resistance factors that are dependent on the type of load tests conducted and are available as a reference to state agencies. The objective of this study was to improve the AASHTO recommended resistance factors used by the Arkansas State Highway and Transportation Department (AHTD), thereby, increasing allowable pile capacity and reducing deep foundation costs. Revised resistance factors for field acceptance based on dynamic testing were established through the analysis of pile load test data where both static and dynamic load testing was conducted. Pile load tests were separated by pile type and soil type. It was important that the load test data analyzed represented soil and geologic conditions similar to those found in Arkansas. The resistance factors determined from this analysis improved AHTD current practice, but indicated that the factors recommended by AASHTO may be unconservative for this region.

Download or read book Static and Wave Equation Analyses and Development of Region specific Resistance Factors for Driven Piles written by Youssef Bougataya and published by . This book was released on 2016 with total page 288 pages. Available in PDF, EPUB and Kindle. Book excerpt: This study uses an existing database of dynamic loading tests of driven piles installed in the Puget Sound Lowlands to improve the reliability of axial performance. First, the unit shaft resistances developed from stress wave signal matching to dynamic records of pile installation are used to develop an effective stress-based shaft resistance model. New, statistically unbiased unit shaft resistance models are proposed for piles driven at End-of-Drive (EOD) and Beginning-of-Restrike (BOR) and for a range of specific soil types and relative densities and consistencies. The accuracy and uncertainty of each model is quantified and compared. Then, the observed unit shaft resistances and proposed design models are used to characterize the magnitude of time-dependent capacity gain. Although these models allow estimation of the range of capacity gain anticipated following pile installation, no reliable time-dependent relationship could be proposed. The study concludes with the quantification of accuracy and uncertainty in dynamic wave equation-based and existing static analysis procedures and calibration of resistance factors for use with load and resistance factor design (LRFD). These resistance factors indicate, in some cases, dramatic improvement in the useable pile capacity at a given reliability owing to the use of a database from a specific region. The results from this work may be immediately applied in practice in the Puget Sound Lowlands.

Download or read book Dynamic Pile Testing Technology written by Robert Y. Liang and published by . This book was released on 2007 with total page 244 pages. Available in PDF, EPUB and Kindle. Book excerpt: Driven piles are widely used as foundations to support buildings, bridges, and other structures. In 2007, AASHTO has adopted LRFD method for foundation design. The probability based LRFD approach affords the mathematical framework from which significant improvements on the design and quality control of driven piles can be achieved. In this research, reliability-based quality control criteria for driven piles are developed based on the framework of acceptance-sampling analysis for both static and dynamic test methods with the lognormal distribution characteristics. As a result, an optimum approach is suggested for the number of load tests and the required measured capacities for quality control of driven piles. Furthermore, this research has compiled a large database of pile set-up, from which the reliability-based approach of FORM is employed to develop separate resistance factors for the measured reference (initial) capacity and predicted set-up capacity. This report also provides a Bayesian theory based approach to allow for combining the information from the static pile capacity calculation and dynamic pile testing data to improve pile design process. Specifically, the results from dynamic pile tests can be utilized to reduce the uncertainties associated with static analysis methods of pile capacity by updating the corresponding resistance factors. This research has also developed one-dimensional wave equation based algorithm to interpret the High Strain Testing (HST) data for the estimation of the shaft and toe resistance of driven piles. The closed form solution is obtained for determining the Smith damping factor and the static soil resistance. Finally, a set of new wireless dynamic testing equipment (both hardware and software) is developed for more efficient dynamic pile testing.

Download or read book Driven Pile Load Test Data for Load and Resistance Factor Design in Missouri written by Joseph Ronson Cravens and published by . This book was released on 2011 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: "The Missouri Department of Transportation (MoDOT) has recently migrated from allowable stress design (ASD) to load and resistance factor design (LRFD) of driven piles. This transition was initiated when the Federal Highway Administration (FHWA) issued a policy stating that all new bridge designs shall be designed in accordance with the American Association of State Highway and Transportation Officials (AASHTO) LRFD Bridge Design Specifications to eliminate the difference in design methodologies for bridge superstructures and bridge substructures. However, the resistance factors for driven piles specified in the AASHTO LRFD specifications are based on nationwide pile data, consisting of a wide range of different geologies, subsurface conditions, and installation procedures. For MoDOT to fully benefit from the transition from ASD to LRFD, resistance factors based on MoDOT's local practices and geologic conditions must be developed. The presented research was dedicated to collecting pile load test data to allow the calibration of resistance factors for ultimate limit state design for predictive methods used by MoDOT to determine pile capacity, as well as to develop related reliability-based quality control criteria of driven pile foundations. MoDOT's current state of practice was evaluated and all available pile load test data was collected. However, MoDOT has records for only 10 pile load tests. Therefore, the search was extended to Missouri's eight neighboring states by distributing questionnaires to surrounding state transportation administrations in hope of gathering pile data. Surrounding states have different geologic conditions, but any collected pile data could be matched to similar soil and rock formations in Missouri's geologic regions. Only five out of eight states responded to the questionnaire, and there was no pile load test data obtained from the states that responded. Therefore, the calibration of resistance factors could not be performed based on the research approaches. The deformation behavior of MoDOT bridge pile foundations was also evaluated at the serviceability limit state by modeling pile foundations in FB-MultiPier. The results indicated that pile displacement is an important factor for the development of serviceability resistance factors for pile foundations. Lastly, recommendations for future MoDOT practice and future research efforts regarding driven piles are provided"--Abstract, leaf iii