Download or read book Base Resistance of Drilled Shafts in Rock written by Stetson B. Ramey and published by . This book was released on 2009 with total page 49 pages. Available in PDF, EPUB and Kindle. Book excerpt: A method is presented to calculate the nominal base resistance of a drilled shaft socketed into a fractured rock mass by using the Hoek-Brown strength criterion and its input parameter the Geological Strength Index (GSI). Base resistance is sometimes neglected when designing drilled shafts embedded in fractured rock masses resulting in large diameter shafts because the entire load is designed to be resisted through side shear. While a fractured rock mass will not have as much bearing capacity as an intact rock mass, usually even a fractured rock mass is able to resist a significant portion of the applied load. Data from load tests on drilled shafts embedded into various types of rock are compared to the theoretical relationship between the GSI and nominal base resistance. The data were all from sources where the drilled shaft was loaded to failure in end bearing and the nominal bearing resistance had been determined. The sources also include necessary rock mass properties. One case was analyzed with the intent of comparing the actual load test data against the theoretical relationship proposed, so rock core boring was taken with the intent of determining a value for the GSI. This data point matches up extremely well with the theoretical relationship. For the other thirteen data points, a value of GSI was estimated from detailed descriptions of the rock mass found in the geotechnical report and boring logs or GSI was correlated to another rock mass rating system. In these cases, the theoretical relationship appears to yield a lower bound to rock socket base resistance. By comparing actual data to the theoretical relationship presented in this thesis, it is determined that the method is a useful tool to estimate the bearing capacity of a rock mass.

Download or read book Drilled Shafts in Rock written by Lianyang Zhang and published by CRC Press. This book was released on 2004-05-15 with total page 396 pages. Available in PDF, EPUB and Kindle. Book excerpt: Drilled shafts in rock are widely used as foundations of heavy structures such as highway bridges and tall buildings. Although much has been learned about the analysis and design of drilled shafts in rock, all the major findings are published in the form of reports and articles in technical journals and conference proceedings. This book i

Download or read book Development of Recommended Resistance Factors for Drilled Shafts in Weak Rocks Based on O Cell Tests written by Xiaoming Yang (Writer on geotechnical engineering) and published by . This book was released on 2010 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt: From October 1, 2007, the new bridges on federal-aid funded projects are mandated to be designed to meet American Association of State Highway and Transportation Officials (AASHTO) Load and Resistance Factor Design (LRFD) Bridge Design Specifications. LRFD is a simplified form of reliability-based design. By multiplying calibrated factors to load and resistance components, the designed structure will maintain a specific level of reliability (or probability of failure). By concept, the load and resistance factors should be calibrated by large number of test data; however, they are often unavailable in geotechnical engineering. Significant efforts are needed to calibrate load and resistance factors based on test data of good quality. In this study, 26 O-Cell test data were collected from Kansas, Colorado, Missouri, Ohio, and Illinois. Seven methods available in the literature were selected to estimate the load capacities of 25 out of 26 drilled shafts. The "FHWA 0.05D" method was found to yield the closest and conservative predictions of the nominal resistances to the representative values; therefore, it was adopted in this study when calibrating the resistance factors for Strength Limit State design. These test data were analyzed and used to calibrate side and base resistance factors for drilled shafts in weak rock. Resistance factors were calibrated at two different target reliability indices: 2.3 (i.e., failure probability, Pf ~ 1/100) for shafts with greater redundancy and 3.0 (Pf ~ 1/1000) for shafts with less redundancy. Side resistance factors were calibrated from two different datasets of measured resistance: total side resistance and layered unit side resistance. The resistance factors calibrated from layered unit side resistance are considered more reliable, therefore, they are recommended for design. The recommended resistance factors from this study are compared with those in AASHTO specifications. Some of those calibrated resistance factors from this study are considerably lower than those in AASHTO specifications. The main reasons for such lower resistance factors are mainly attributed to the low efficiency of the FHWA design method and the limited quality and number of O-Cell test data. These resistance factors may be improved by increasing the size and the quality of the test data in the future. At present, field load tests on drilled shafts are recommended as an alternative to using lower resistance factors, which will also accumulate more test data for future improvement.

Download or read book Drilled Shaft Design and Construction Guidelines Manual Construction procedures and design for axial loading written by Lymon C. Reese and published by . This book was released on 1977 with total page 152 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Rock socketed Shafts for Highway Structure Foundations written by John P. Turner and published by Transportation Research Board. This book was released on 2006 with total page 145 pages. Available in PDF, EPUB and Kindle. Book excerpt: TRB's National Cooperative Highway Research Program (NCHRP) Synthesis 360: Rock-Socketed Shafts for Highway Structure Foundations explores current practices pertaining to each step of the design process, along with the limitations; identifies emerging and promising technologies; examines the principal challenges in advancing the state of the practice; and investigates future developments and potential improvements in the use and design of rock-socketed shafts.

Download or read book Drilled Shaft Manual Construction procedures and design for axial loading written by Lymon C. Reese and published by . This book was released on 1977 with total page 152 pages. Available in PDF, EPUB and Kindle. Book excerpt: Drilled shafts have been used on a limited scale for many years as an alternative to driven piles in a variety of foundation problems. However, uncertainty about the behavior of the drilled shaft has forestalled widespread adoption. The subject package, by Dr. Lymon C. Reese of the University of Texas, is intended for use by bridge engineers, geotechnical engineers, and builders of pile foundations. The manual contains rational procedures and practical guidelines for the design and construction of drilled shaft foundations. Volume I presents a rational design procedure for drilled shafts under axial loading and includes guidelines on construction methods, inspection, load testing, specifications, and cost estimates. Volume II presents alternative methods for computing the response of the shaft to lateral loading and presents the structural design of the shaft for axial and/or lateral loading.

Download or read book Drilled Shafts written by Michael W. O'Neill and published by . This book was released on 1999 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Improved Design Economy for Drilled Shafts in Rock written by and published by . This book was released on 2002 with total page 154 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Drilled Shaft Design and Construction Guidelines Manual Reese L C and Allen J D Structural analysis and design for lateral loading written by Lymon C. Reese and published by . This book was released on 1977 with total page 398 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Drilled Shafts in Rock written by Lianyang Zhang and published by CRC Press. This book was released on 2004-05-15 with total page 398 pages. Available in PDF, EPUB and Kindle. Book excerpt: Drilled shafts in rock are widely used as foundations of heavy structures such as highway bridges and tall buildings. Although much has been learned about the analysis and design of drilled shafts in rock, all the major findings are published in the form of reports and articles in technical journals and conference proceedings. This book i

Download or read book Drilled Shaft Design and Construction Guidelines Manual written by Lymon C. Reese and published by . This book was released on 1977 with total page 152 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Drilled Shafts written by National Highway Institute (U.S.) and published by . This book was released on 1988 with total page 608 pages. Available in PDF, EPUB and Kindle. Book excerpt: This document was written as a resource for participants in a short course covering the topic of construction and design of drilled shaft foundations for bridges and other structures. It is the second edition of a Federal Highway Administration workbook on construction and design of drilled shafts. The first edition was written in 1988 (FHWA-SA-HI-88-042). While introductory material from the 1988 edition was retained, the emphasis in this document is on providing relatively comprehensive information for engineers who already have some experience with drilled shaft construction and/or design. The initial chapters cover an overview of the characteristics of drilled shafts, site investigations for drilled shafts (to collect information for both construction and design), and details of drilled shaft construction. These chapters are followed by several chapters on the design of drilled shafts in soil and rock for both axial and lateral loading, with examples. Both allowable stress design and load and resistance factor design principles are addressed. Details of design calculations procedures are provided in the appendices.

Download or read book Overview for Design and Construction of Drilled Shafts in Cohesive Soils written by Lawrence D. Johnson and published by . This book was released on 1981 with total page 132 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Side Resistance of Drilled Shafts in Weak Rock written by Eric W. Sandberg and published by . This book was released on 1993 with total page 194 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Load and Resistance Factor Design of Drilled Shafts in Shale Using Standard Penetration Test and Texas Cone Penetration Test Measurements written by Mark Daniel Pierce and published by . This book was released on 2013 with total page 174 pages. Available in PDF, EPUB and Kindle. Book excerpt: Missouri Department of Transportation (MoDOT) designers currently follow American Association of State Highway and Transportation Officials (AASHTO) design methods for design of drilled shafts in shale and other weak rock. These methods are generally based on Load and Resistance Factor Design (LRFD) methods that relate uniaxial compressive strength measurements of rock cores to the side and tip resistance for drilled shafts. However, shale and other weak rock can be notoriously difficult to effectively sample and test, which poses practical problems for those tasked with designing drilled shafts in such materials. The difficulty in sampling shale has lead geotechnical engineers to consider in-situ tests, such as the Standard Penetration Test (SPT) and the Texas Cone Penetration test (TCP), as surrogates for conventional coring and laboratory testing. In order to utilize results of in-situ tests for design of drilled shafts using Load and Resistance Factor Design (LRFD), it is necessary to correlate in-situ test measurements with side and tip resistance and to establish calibrated resistance factors that account for the reliability of the correlations and the in-situ test measurements. This thesis describes efforts undertaken to develop improved correlations among in-situ test measurements and drilled shaft capacity and to develop resistance factors that produce established target reliabilities for different classes of roadways.

Download or read book Principles of Foundation Engineering written by Braja M. Das and published by Cengage Learning. This book was released on 2018-10-03 with total page 944 pages. Available in PDF, EPUB and Kindle. Book excerpt: Master the core concepts and applications of foundation analysis and design with Das/Sivakugan’s best-selling PRINCIPLES OF FOUNDATION ENGINEERING, 9th Edition. Written specifically for those studying undergraduate civil engineering, this invaluable resource by renowned authors in the field of geotechnical engineering provides an ideal balance of today's most current research and practical field applications. A wealth of worked-out examples and figures clearly illustrate the work of today's civil engineer, while timely information and insights help readers develop the critical skills needed to properly apply theories and analysis while evaluating soils and foundation design. Important Notice: Media content referenced within the product description or the product text may not be available in the ebook version.

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