Author: Thomas G. LewisPublisher:
ISBN:
Category :
Languages : en
Pages : 272
Book Description
Analysis of Axially and Laterally Loaded Rock-socketed Drilled Shafts with Steel Casings
Author: Thomas G. LewisAnalysis of Laterally Loaded Drilled Shafts in Rock
Author: Ke YangPublisher:
ISBN:
Category : Lateral loads
Languages : en
Pages : 536
Book Description
Drilled shafts socketed into rock are widely used as foundations for bridges and other important structures. Rock-socketed drilled shafts are also used to stabilize a landslide. The main loads applied on the drilled shafts are axial compressive or uplift loads as well as lateral loads with accompanying moments. Although there exist several analysis and design methods especially for rock-socketed drilled shafts under lateral loading, these methods were developed with assumptions without actual validations with field load test results. Some of the methods have been found to provide unsafe designs when compared to recently available field test data. Therefore, there is a need to develop a more rational design approach for laterally loaded drilled shafts socketed in rock. A hyperbolic non-linear p-y criterion for rock is developed in this study that can be used in conjunction with existing computer programs, such as COM624P, LPILE, and FBPIER, to predict the deflection, moment, and shear responses of a shaft under the applied lateral loads. Considerations for the effects of joints and discontinuities on the rock mass modulus and strength are included in the p-y criterion. Evaluations based on comparisons between the predicted and measured responses of full-scale lateral load tests on fully instrumented drilled shafts have shown the applicability of the proposed p-y criterion and the associated methods for determining the required input of rock parameters. In addition to the development of a hyperbolic p-y criterion for rock, a method for predicting lateral capacities of drilled shafts in rock and/or soils is developed for assessing the safety margin of the designed shafts against the design loads. A computer program LCPILE is developed using VC++ to facilitate computations. An elastic solution based on a variational approach is also developed for determining drilled shaft elastic deflection due to applied lateral loads in a two-layer soil layer system. The computational algorithm was coded in a Mathematical file for easy application. Finally, Briaud's method for deriving p-y curves of rock from pressuremeter or dilatometer test results is evaluated using available field test data. A modification to the Briaud's method is recommended for applications in rocks.
Rock-socketed Shafts for Highway Structure Foundations
Author: John P. TurnerPublisher: Transportation Research Board
ISBN: 0309097681
Category : Bridges
Languages : en
Pages : 145
Book Description
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.
Drilled Shaft Manual: Structural analysis and design for lateral loading by
Author: Lymon C. ReesePublisher:
ISBN:
Category : Shafts (Excavations)
Languages : en
Pages : 244
Book Description
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.
Case History Evaluation of the Behavior of Drilled Shafts Under Axial and Laterial Loading
Author: Yit-Jin ChenDrilled Shafts in Rock
Author: Lianyang ZhangPublisher: CRC Press
ISBN: 0203024427
Category : Technology & Engineering
Languages : en
Pages : 398
Book Description
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
Drilled Shaft Design and Construction Guidelines Manual: Reese, L. C., and Allen, J. D., Structural analysis and design for lateral loading
Author: Lymon C. ReesePublisher:
ISBN:
Category : Bridges
Languages : en
Pages : 246
Book Description
Resistance Analysis of Axially Loaded Drilled Shafts Socketed in Shale
Author: Terry Bryce BurkettPublisher:
ISBN:
Category :
Languages : en
Pages : 436
Book Description
An investigation into the load-settlement behavior of two drilled shafts, founded in shale, is presented. The motivation for this research is to advance the understanding on how drilled shafts react under loading in stiff clays and shales. The objectives of the study are to measure the strengths within the subsurface material at the test site, estimate the unit side shear and unit end bearing of the shale-shaft interaction by running two axial load tests, and compare the results to the current design methods that are used to predict the axial capacity of drilled shafts. A comprehensive field investigation, performed by Fugro Consultants, provided strength profiles of the subsurface material at the test site. Through the cooperation of the Texas Department of Transportation (TxDOT), the Association of Drilled Shaft Contractors, and McKinney Drilling Company, two drilled shafts were installed at a highway construction site in Austin, Texas. The load tests were performed by Loadtest, Inc.; using the patented Osterberg-CellTM loading technique to axially displace the shafts. Ensoft, Inc. installed strain gauges at multiple levels within the shafts, making it possible to analyze the shaft mobilization during loading. Ultimate end bearing values of about 100- and 120-ksf were measured for Test Shafts #1 and #2, respectively. The current methods for estimating unit end bearing, developed by TxDOT and the Federal Highway Administration, provide fairly accurate predictions when compared to the measured information. The ultimate side resistance obtained near the O-CellTM in each test was about 20-ksf, however, the measured ultimate side resistance steadily decreased nearing the tip of the shaft. For the zones where the side resistance was believed to be fully mobilized, the TxDOT design method accurately predicts the side resistance. A limited amount of information is currently available for load tests performed in soils with TCP values harder than 2-in per 100 blows. Additional load test information should allow for a stronger correlation between TCP tests and unit resistances for very hard clay-shales, as well as, allowing for further evaluation of the shale-shaft interaction near the shaft tip. The results presented herein demonstrate the effectiveness of the current design methods for drilled shafts and the non-uniformity of side resistance within one- to two-diameters of the shaft tip.
Analysis and Design of Axially Loaded Drilled Shafts Socketed Into Rock
Author: Lianyang ZhangDesign of Rock Socketed Drilled Shafts
Author: Jamal NusairatPublisher:
ISBN:
Category : Bridges
Languages : en
Pages : 422
Book Description
This project was aimed at evaluating and developing design methods for laterally loaded drilled shafts socketed in rock. Five lateral load tests on rock socketed drilled shafts with full range of instrumentation were conducted in Ohio. Detailed instrumentation included the use of vibrating wire strain gages, inclinometers, dial gages, and load cells. P-y curves representing site-specific lateral shaft-rock interaction were deduced from strain data. Field testing included the use of a borehole pressuremeter/dilatometer to obtain measurements that were correlated with rock mass strength and deformation parameters as well as with p-y curves. A comparison was made between the baseline p-y curves deduced from strain data of lateral load tests, the p-y curves predicted by using Reese's interim criterion, and the p-y curves from the pressuremeter tests in rock. A new hyperbolic p-y criterion for rock is proposed based on the field test data and extensive theoretical work. Validation of the proposed p-y criterion of rock was carried out by comparing the predictions of shaft deflections and bending moments using the hyperbolic p-y criterion against actual lateral load tests results. Based on the findings of this study, a complete solution for the design of drilled shafts socketed in rock or intermediate geomaterials under lateral loads is provided.