A Stratified Percolation Model for Saturated and Unsaturated Flow Through Natural Fractures
The geometry of the asperities of contact between the two surfaces of a fracture and of the adjacent void spaces determines fluid flow through a fracture and the mechanical deformation...
Study of Fractal Aperture Distribution and Flow in Fractures
This study examines the roughness profiles and aperture distributions of fractures and faults by using concepts from fractal geometry. Simple models of flow of fluid in rough fractures...
Drill-Back Studies Examine Fractured, Heated Rock
To investigate the effects of heating on the mineralogical, geochemical, and mechanical properties of rock by high-level radioactive waste, cores are being examined from holes penetrating...
Building of a Conceptual Model at the UE25-C Hole Complex
U.S. Geological Survey and Lawrence Berkeley Laboratory are attempting to construct a conceptual model of the UE25-c hole complex. An interdisciplinary approach is discussed where all...
Combined Analytical/Numerical Approaches to Solving Fluid Flow Problems in the Unsaturated Zone at Yucca Mountain
Various analytical and numerical approaches are presented for the study of unsaturated flow processes in the vicinity of the Yucca Mountain, Nevada, the proposed site of an underground...
An Investigation of the Mechanical and Hydrologic Behavior of Tuff Fractures Under Saturated Conditions
The mechanical and hydrologic behavior of natural-fractures in a partially welded tuff rock were investigated. Tuff cores, each containing part of the same natural fracture oriented subparallel...
Diffusion Coefficients and Hydraulic Conductivity in Unsaturated Hanford Soils and Sediments
Two groundwater transport parameters of some Hanford formation materials, the hydraulic conductivity and the diffusion coefficient, were measured to aid in predicting contaminant migration....
Seismic Characterization of Fracture Properties
Laboratory measurements of the mechanical stiffness, hydraulic conductivity and seismic properties of three natural fractures were made as a function of applied normal stress. Seismic...
Motion Control of Space Structures
A new area of civil engineering is emerging as we begin to establish a permanent presence in space. The new area of civil engineering is the motion control of space structures. This paper...
Actively Controlled Optimum Structural Design
This paper deals with the investigation of the number and location of actuators and sensors on the optimum structure and control design of space structures. The optimization problem is...
Space Construction: A CSI Perspective
This paper outlines the control structure interaction (CSI) problem for space construction engineers. An overview of the Control Astrophysics and Structures Experiment in Space (CASES)...
Planning Model for Sewer System Rehabilitation
A probabilistic model is developed to simulate long-term variation in the structural condition of wastewater collection systems. The effects of both deterioration and rehabilitation can...
A Design Process for Water Distribution Systems Including Optimization
Design of a water distribution system is a multi-level process from preliminary planning to final detailed sizing of components. Unfortunately as in many design problems, a final detailed...
Upgrading Hydraulic Infrastructure for Level One Redundancy
In the current paper a methodology is presented for upgrading any single source water distribution system in order to provide a level one system redundancy at a minimum cost. A level one...
Predicting Watermain Breakage Rates
Recent studies on water main breakage have shown significant spatial and temporal clustering in the breakage pattern. The methodology described in the paper provides the basis for a prediction...
Rehabilitation Model for Water Distribution Systems
This paper presents an optimization model for determining the minimum cost rehabilitation and replacement of pipes in water distribution systems. The advantages of the proposed model include...
Models for Optimal Maintenance of Hydraulic Structures
Corrective maintenance includes the unscheduled repairs required to return a structure from a failed state to an operating or available state. Corrective maintenance is determined by the...
Reliability Estimation for Vertical Lift Gate at Emsworth Dam
The lift gates are composed of two horizontal trusses, two vertical girders, seven diaphragms, and two end frames. A critical element in the structural integrity of the lift gate is a...
Urban Drainage Pipe Systems: Failure Diagnosis and Rehabilitation Planning
A Task Committee on Failure Diagnosis and Rehabilitation of Urban Drainage Infrastructure has been organized by the Urban Water Resorces Committee of the Water Resourcs Planning and Management...
The New Generation of Pipeline Rehabilitation
The new advancements in pipelines reconstruction technologies now permit total sewer system rebuilding of collectors, drainlines, manholes, service laterals, and force mains without excavation....
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