Author: Robert M. EbelingPublisher:
ISBN:
Category : Concrete dams
Languages : en
Pages : 276
Book Description
Evaluating the Stability of Existing Massive Concrete Gravity Structures Founded on Rock
Author: Robert M. EbelingPublisher:
ISBN:
Category : Concrete dams
Languages : en
Pages : 276
Book Description
Repair, Evaluation, Maintenance and Rehabilitation Research Program: Evaluating the Stability of Existing Massive Concrete Gravity Structures Founded on Rock
Author: Publisher:
ISBN:
Category :
Languages : en
Pages : 267
Book Description
The U.S. Army Corps of Engineers is responsible for designing and maintaining a large number of navigation and flood control structures. Many of the older massive concrete gravity hydraulic structures are being examined to determine if rehabilitation is required to meet stability criteria. The procedures currently used for evaluating the safety of existing massive hydraulic structures are the conventional equilibrium methods, which are the same general methods used in the design of these structures. Because the conditions of equilibrium are insufficient for a complete analysis of all aspects of structure foundation interaction involved in the stability and performance of these structures (soil structure foundation interaction in the case of earth retaining structures), these conventional equilibrium methods necessarily involve assumptions regarding aspects of the loading forces and the resisting forces that act on the hydraulic structures. Differences between actual field performance and calculations from conventional analysis have been noted for some existing hydraulic structures. Conventional design methods were developed based largely on classical limit equilibrium analysis without regard to deformation related concepts. Today, analytical tools such as the finite element method (FEM) are available which consider the manner in which the loads and resistance are developed as a function of the stiffnesses of the foundation rock, the structure foundation interface, and rock joints within the foundation. These analytical tools provide a means to evaluate the conventional equilibrium-based design methods used to evaluate the safety of existing hydraulic structures, and specifically, to identify and investigate key assumptions used in safety calculations from the conventional analysis.
Repair, Evaluation, Maintenance, and Rehabilitation Research Program. Re-Evaluation of the Sliding Stability of Concrete Structures on Rock with Emphasis on European Experience
Author: K. KovariPublisher:
ISBN:
Category :
Languages : en
Pages : 71
Book Description
The sliding stability of a rock mass forming the foundation or the abutments of concrete dames, of a natural slope, or of a cut cannot be measured directly but merely conjectured. One knows, however, the nature of the mechanisms which may lead to a failure, and, conversely, remedial measures which may enhance the existing stability. Attention must be paid to sliding hazard if the presence of adversely oriented discontinuities with considerable persistence is evident, if movements take place in the rock mass, if high water pressures are measured in faults, and/or if wet spots at critical areas of a slope or downstream of the dam foundation are known to occur. A changes in the flow rate of the drains can also be an indication of an unsafe condition. The most effective way and, in many instances, the only practical solution to increase stability against sliding is to prevent or to eliminate the occurrence of excessive water pressure below the foundation or in the faults. The second possibility involves reinforcements by anchoring and shear keys, and the third is removal or placement of rock masses and concrete in critical areas. The problem which arises in practice is to weigh correctly the different pieces of information relating to the assessment of the degree of stability. The aim of the authors is to draw attention to recent developments in stability analysis and in rock mass behaviour monitoring which may be helpful, in dealing with the problems encountered in practice. (kr).
Le musée royal ou recueil de gravures d'après les plus beaux tableaux, statues et bas-reliefs de la collection royale
Author: Energy and Water Development Appropriations for 2000
Author: United States. Congress. House. Committee on Appropriations. Subcommittee on Energy and Water DevelopmentPublisher:
ISBN:
Category : Energy development
Languages : en
Pages : 1106
Book Description
Survey of Stability Investigations of Concrete Structures on Rock
Author: Larry SchlahtPublisher:
ISBN:
Category :
Languages : en
Pages : 4
Book Description
Omaha District personnel conducted a survey in early 1985 pertaining to methods and criteria used on completed and ongoing stability investigations for Corps of Engineers concrete structures on rock foundations. This effort was funded under the Repair, Evaluation, Maintenance and Rehabilitation (REMR) Research Program and a draft report on the survey was completed by the Omaha District in June 1985.
Government Reports Annual Index
Author: Publisher:
ISBN:
Category : Government publications
Languages : en
Pages : 1128
Book Description
Repair, Evaluation, Maintenance, and Rehabilitation Research Program. The Condition of Corps of Engineers Civil Works Concrete Structures
Author: J. E. McDonaldPublisher:
ISBN:
Category :
Languages : en
Pages : 136
Book Description
Two computerized data bases, (a) structure-description and (b) damage and repair, were compiled. The structure-description data base contains basic information (location, category, age, purpose, etc.) on 766 projects. The damage and repair data base contains information on the current condition of the concrete in the Corps' civil works structures as determined through detailed reviews of over 2000 periodic inspection reports. To assist in the analysis, a number of computer programs were developed to manipulate and search the data bases. This analysis concentrated on the types of deficiencies observed, the cause (if reported), location within the structure, and degree of damage. Also, if the deficiency had been repaired, the material or technique or boh that were used and the performance were analyzed. This identification and assessment of problems relating to evaluation, maintenance, and repair of concrete will provide guidance in developing and establishing priorities for research in the Repair, Evaluation, Maintenance, and Rehabilitation (REMR) Research Program. Originator-supplied keywords: Causes of concrete deficiencies; Concrete structures; Condition evaluations; Damage to concrete; Deficiencies in concrete; Hydraulic structures; Maintenance of concrete; Repair of concrete; REMR (Repair, Evaluation, Maintenance, and Rehabilitation) Research Program.
Repair, Evaluation, Maintenance, and Rehabilitation Research Program. Laboratory Evaluation of Concrete Mixtures and Techniques for Underwater Repairs
Author: Publisher:
ISBN:
Category :
Languages : en
Pages : 90
Book Description
Concrete mixtures were placed underwater using six placement techniques to (a) examine the cohesive and flow parameters of selected concrete mixtures under different placement situations, (b) estimate those parameters necessary for successful underwater placement, (c) examine the quality of bonding of the repair concrete to the existing concrete, and (d) examine the effect of underwater placement upon the abrasion resistance of the concrete. A washout test was used to determine the relative amount of cement paste lost when the concrete is exposed to a large volume of water. The two-point workability test was used to evaluate the relative workability properties of the concrete. The slump, tremie flow, and air content were also measured. The test method for abrasion-erosion resistance of concrete (underwater method) was used to determine the abrasion-erosion resistance of each concrete. A point-load test for tensile strength was used to determine the bond strength of the repair concrete to the existing concrete.
Author: