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Book Development of Resistance Factors for Axial Capacity of Driven Piles in North Carolina

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.

Book Development of Resistance Factors for Axial Capacity of Driven Piles in North Carolina

Download or read book Development of Resistance Factors for Axial Capacity of Driven Piles in North Carolina written by Kyung Jun Kim and published by . This book was released on 2002 with total page 276 pages. Available in PDF, EPUB and Kindle. Book excerpt: Keywords: pile bearing capacity, load and resistance factor design, Vesic, Nordlund, Meyerhof, reliability analysis, FORM, MVFOSM, AFOSM, resistance factor calibration, pile driving analyzer, static load test, bias factor.

Book Calibration of Resistance Factors for Axial Capacity of Driven Pile Into Missouri Soil

Download or read book Calibration of Resistance Factors for Axial Capacity of Driven Pile Into Missouri Soil written by Mulugeta Abay Kebede and published by . This book was released on 2010 with total page 270 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Over the past two decades the load resistance factor design (LRFD) has been accepted by the American Association for Transportation and Highway Officials (AASHTO) for the design of bridges. This approach is now gaining widespread popularity in the United States for substructure bridge design, including the design of driven pile foundations, as the states calibrate the geotechnical resistance factors for local geological conditions and practices. This study presents the geotechnical resistance factors calibrated for axially driven pile using the first-order reliability method (FORM) for the target reliability index of 2.33 and 3.0 based on 64 end-of-drives (EOD) and 22 beginning-of restrike (BOR) pile driving analyzer (PDA) test data from nine bridge sites in Missouri. Three static pile capacity prediction methods were used, i.e. the Nordlund, Meyerhof and Beta methods. The work investigated the efficiency of each method based on the bias factor, the ratio of the measured to the predicted capacity of the pile, ([lambda] = R[subscript m]/R[subscript p]), the coefficient of variation (COV), and efficiency factor or the ratio of the resistance factor to the bias factor, ([phi]/[lambda]). It verified that the Beta and Nordlund methods provide better predictions than the Meyerhof method. In addition, a comparison of the resistance factor in current AASHTO LRFD with the calibrated resistance factor shows that validating the resistance factors in the AASHTO may result in less reliable design. Finally, the recommended resistance factors for LRFD design are provided for use in Missouri. In addition, further refinement of the developed resistance factors is recommended to improve the resistance factors using large quantity and high quality of data that cover wide areas the glaciated plain and southeast lowland geological regions"--Abstract, leaf iii.

Book Development of Load and Resistance Factor Design Procedures for Driven Piles on Solf Rocks in Wyoming

Download or read book Development of Load and Resistance Factor Design Procedures for Driven Piles on Solf Rocks in Wyoming written by University of Wyoming. Department of Civil and Architectural Engineering and published by . This book was released on 2019 with total page 156 pages. Available in PDF, EPUB and Kindle. Book excerpt: "The overall goal of the research project is to develop locally calibrated LRFD procedures (i.e., design methodologies and resistance factors) for driven piles on soft rocks in Wyoming." -- page 3.

Book Load and Resistance Factor Design and Construction Control of Driven Piles in Intermediate Geomaterials

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.

Book Developing Production Pile Driving Criteria from Test Pile Data

Download or read book Developing Production Pile Driving Criteria from Test Pile Data written by Dan A. Brown and published by Transportation Research Board. This book was released on 2011 with total page 518 pages. Available in PDF, EPUB and Kindle. Book excerpt: TRB’s National Cooperative Highway Research Program (NCHRP) Synthesis 418: Developing Production Pile Driving Criteria from Test Pile Data provides information on the current practices used by state transportation agencies to develop pile driving criteria, with special attention paid to the use of test pile data in the process.

Book Static and Wave Equation Analyses and Development of Region specific Resistance Factors for Driven Piles

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.

Book Dynamic Pile Testing Technology

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.

Book Development of LRFD Driven Pile Resistance Factor by First Order Second Moment Method in Alabama Soils

Download or read book Development of LRFD Driven Pile Resistance Factor by First Order Second Moment Method in Alabama Soils written by Elisa D. Prado Villegas and published by . This book was released on 2015 with total page 154 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Load and Resistance Factor Design LRFD for Driven Piles Using Dynamic Methods A Florida Perspective

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.

Book Development and Implementation of the DIGGS Format to Perform LRFD Resistance Factor Calibration of Driven Concrete Piles in Florida

Download or read book Development and Implementation of the DIGGS Format to Perform LRFD Resistance Factor Calibration of Driven Concrete Piles in Florida written by Mark Anthony Styler and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: ABSTRACT: National Cooperative Highway Research Program (NCHRP) Report 507 demonstrates that the difference between FORM and FOSM resistance factor calibrations can be up to 15%. With some pile caps containing in excess of 25 piles, millions could be saved if this difference could be accounted for. Currently, the more conservative FOSM is used instead of designing for a specific probability of failure. This thesis explored the difference between FOSM and FORM using DIGGS, a newly developed standard for digitally storing geotechnical data. The DIGGS standard was developed and documented and a DIGGS file containing 62 prestressed concrete piles from the State of Florida was created. These piles were also analyzed with the Bridge Software Institute s FB-Deep program to predict Davission Failure limits. Resistance factors were then calculated using both FOSM and FORM for the Davission Limit using FB-Deep. The results found agreed with the NCHRP 507 with FORM resistance factor calibrations being 8% to 23% greater than FOSM. Following this, a corrected FOSM equation was derived which agrees with the FORM results. Using the modified FOSM equation resistance factors can be more accurately predicted. Designers should recognize that using the larger resistance factors results in a larger probability of failure, but more importantly it results in a known probability of failure.