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In 2013, the Federal Highway Administration proposed a new research program for the characterization of bridge foundations. To narrow the focus and develop a research roadmap for the program, a workshop on Characterization of Brid...
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In 2013, the Federal Highway Administration proposed a new research program for the characterization of bridge foundations. To narrow the focus and develop a research roadmap for the program, a workshop on Characterization of Bridge Foundations was held in Arlington, VA, from April 30 to May 1, 2013, to solicit key stakeholder input. The workshop opened with plenary sessions to provide the invited participants with a national perspective on the issue; summaries of geotechnical and hydraulic hazards; and, the impact of changes in service loads and foundations reuse. The plenary sessions were followed by breakout sessions. This report presents an overview and documents the results and conclusions of the workshop.
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The report presents: anticipated site conditions which would affect information requirements; potential foundation schemes used to identify key geotechnical parameters; techniques available for exploration and site characterizatio...
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The report presents: anticipated site conditions which would affect information requirements; potential foundation schemes used to identify key geotechnical parameters; techniques available for exploration and site characterization; and geologic and geotechnical factors and uncertainties that may be associated with site exploration and design information.
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The problems of obtaining frozen samples by core drilling of perennially frozen gravel and rock were investigated. Most of the core drilling was carried out in ice-bonded,well-graded alluvial gravel with the ground temperature nea...
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The problems of obtaining frozen samples by core drilling of perennially frozen gravel and rock were investigated. Most of the core drilling was carried out in ice-bonded,well-graded alluvial gravel with the ground temperature near its freezing point. Both chilled compressed air and oil-based liquids were used as drilling fluids. The details of both successful and unsuccessful coring attempts are reported and related to descriptions and photographs of samples of a wide range of quality. Drilling variables such as weight on the bit,rotational velocity,rate of penetration,fluid temperatures,viscosities,flow rates and pressures and mechanical details of the diamond bits are reported. (Modified author abstract)
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This report describes the study of piles tested in polar snow at Camp Century, Greenland. More than 20 piles of various lengths and sizes were driven, including timber, closed-end and open-end steel pipe piles, and I- and H-piles....
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This report describes the study of piles tested in polar snow at Camp Century, Greenland. More than 20 piles of various lengths and sizes were driven, including timber, closed-end and open-end steel pipe piles, and I- and H-piles. The H-piles were instrumented with strain gages. In addition to the driven piles, two purely end-bearing piles were installed in augered holes and five piles were frozen in place using a snow-water slurry. Driving records were obtained and are discussed. Analysis of the driving response of various piles revealed that the Hiley formula, and presumably other similar pile driving formulas, cannot be used to predict the ultimate supporting capacity of piles driven in snow. Factors such as pile inertia, rigidity, size, and tip resistance are discussed in relation to their apparent influence upon pile penetration. Pile load test procedures are described and test results are discussed. It was found that closed-end pipe piles are decidedly inferior to open-end pipe piles in their load-carrying capability and their ultimate supporting capacity. Although pile settlement was found to be dependent upon such variables as pipe load, time, pile shape, and snow temperature, precise effects of these variables were not determined. Nevertheless, the capability of open-end piles to carry quite heavy loads was demonstrated and a procedure is presented for testing these piles in snow.
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Quantitative information on the response of soil in natural deposits to lateral loadings was obtained by the performance of field tests in conjunction with theoretical studies and in-situ and laboratory determinations. The field t...
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Quantitative information on the response of soil in natural deposits to lateral loadings was obtained by the performance of field tests in conjunction with theoretical studies and in-situ and laboratory determinations. The field tests utilized a segmental pile, a lateral plate loading device, rigid poles subjected to lateral loads, and full-scale laterally loaded piles. Results of the final series of field tests and analytical studies in the program are presented in this report, along with the design recommendations formulated on the basis of the research. Procedures were developed for the prediction of nonlinear lateral soil pressure-displacement relationships applicable to undisturbed deposits of both cohesive and noncohesive soils using easily measured conventional engineering properties of the soil. These procedures were utilized in the development of design procedures for laterally loaded piles in nonhomogeneous layered soil system. An iterative solution of the laterally loaded pile problem utilizing a digital computer was developed, and a similar iterative solution for hand computations in a tabular form was evolved for use in cases where a computer cannot be used. (Author)
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This report presents recommended procedures and practices for the design and performance evaluation of pile foundations for bridges in areas subject to lateral spreading hazards. The past decade of research has produced numerous i...
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This report presents recommended procedures and practices for the design and performance evaluation of pile foundations for bridges in areas subject to lateral spreading hazards. The past decade of research has produced numerous insights into the behavior and performance of pile foundations and bridges impacted by liquefaction and lateral spreading. The purpose of this report is to develop a set of recommended procedures and practices for analysis and design that are based on a synthesis of research findings when supporting research is available, and on the professional opinions of the Principal Investigators when supporting research is lacking. The scope of the report is to summarize those recommendations in a concise document that provides references to supporting materials and/or identifies areas where supporting materials are lacking. This report is intended for engineers who are familiar with geotechnical and structural design practice for static and seismic loading of bridges. The pile foundations covered by these recommendations include all piles included in the Caltrans Standard Specifications (Caltrans 2006). The term 'lateral spreading' in this document refers to global movements of soil due to liquefaction of underlying cohesionless soil and hence includes cases that might be described as flow liquefaction (e.g., slope instability). The recommendations presented herein focus on the effects of liquefaction and lateral spreading, and assume familiarity with the necessary background information.
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A series of nine spread footing tests was installed on snow at Camp Century, Greenland, in 1961 and continuously observed through the 1963 summer season. The influence of footing load, size and shape on settlement were investigate...
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A series of nine spread footing tests was installed on snow at Camp Century, Greenland, in 1961 and continuously observed through the 1963 summer season. The influence of footing load, size and shape on settlement were investigated and the effects of the uncontrolled parameters temperature and snow density were recorded. (Author)
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This report includes results of review of 23 grouting case histories at 14 Corps of Engineers projects constructed over a 4-decade period. Corps grouting practices, including technical requirements, contractual procedures, and con...
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This report includes results of review of 23 grouting case histories at 14 Corps of Engineers projects constructed over a 4-decade period. Corps grouting practices, including technical requirements, contractual procedures, and construction management of grouting work are analyzed. Results of the grouting projects are evaluated and costs are analyzed along with legal decisions and trends. The report identifies areas of needed improvements in the Corps grouting programs and makes specific recommendations for achieving those improvements.
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摘要 :
This report includes results of review of 23 grouting case histories at 14 Corps of Engineers projects constructed over a 4-decade period. Corps grouting practices, including technical requirements, contractual procedures, and con...
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This report includes results of review of 23 grouting case histories at 14 Corps of Engineers projects constructed over a 4-decade period. Corps grouting practices, including technical requirements, contractual procedures, and construction management of grouting work are analyzed. Results of the grouting projects are evaluated and costs are analyzed along with legal decisions and trends. The report identifies areas of needed improvements in the Corps grouting programs and makes specific recommendations for achieving those improvements.
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This report describes a study that extends solutions for mathematical analysis of seepage berms presented in 'Investigation of Underseepage and Its Control Lower Mississippi River Levees,' Technical Memorandum 3-424, Vol 1, Octobe...
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This report describes a study that extends solutions for mathematical analysis of seepage berms presented in 'Investigation of Underseepage and Its Control Lower Mississippi River Levees,' Technical Memorandum 3-424, Vol 1, October 1956, US Army Engineer Waterways Experiment Station. A plot of the required seepage berm width, B, versus the ratio of the permeability of the berm to the top blanket, K, for various safety factors indicates B is very sensitive to K for K < or = 1. When the uplift safety factor varies from 1.5 at the landside levee toe to 1.0 at the landside seepage berm toe, the berm width is only slightly greater than that for a uniform safety factor of 1.0. If the uplift safety factor is greater than 1.0 at the berm toe, then as the top blanket becomes thinner, the berm width becomes longer. Thus, other methods of underseepage control should be investigated to determine whether they may be more economical. When the seepage berm is impervious, the berm width is a maximum. When the seepage berm is infinitely pervious, the berm width is a minimum. Therefore, seepage berms should be constructed of the most pervious soils available (with adequate provisions for control of surface erosion and internal piping) in the interest of economy. Because of the great difficulty in determining the permeability of the foundation, top blanket, and seepage berm, the mathematical solutions presented in this report should be used only as a guide to good engineering judgement. A range of permeability values should be used rather than average values.
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