Nearby Utilities Research Articles

Effect of Rock Trenching Vibrations on Nearby Structures

Trenching to install deep gravity sewers and drains in medium-to high-strength rock requires large and heavy rock trenchers that produce high levels of vibrations that may affect the structural integrity of nearby utilities and buildings. Although not every vibration causes damage, owners often believe that their structures have been harmed by rock excavation. The resulting disputes can waste a great deal of time and money. In an effort to reduce structural damage and associated disputes, this paper provides guidelines for the safe distance between rock trenchers and nearby buildings and underground structures. Vibration data at different distances from the trencher centerline were collected from five trenching projects in Northwest Ohio. The data analysis suggests a moderate relationship between the vibration level and the distance from the source of vibration. In addition, the risk of damage to nearby structures dissipates significantly and quickly as the distance from the point of excavation increases. Rock trenching should not take place closer than 1.50 m for buried structures and 1.00 m for residential buildings. Beyond this safe distance, damage to nearby structures should not take place.

Digital image reasoning for tracking excavation activities

Efficient and safe construction of underground space is a key aspect in the development of infrastructure within densely populated urban environments. Construction processes are usually adjusted, based on information collected from field monitoring, to control induced ground movements such that the impact on nearby structures and utilities is minimized. An important component of field monitoring includes the development of a detailed timeline record of various construction activities especially soil removal. This paper explores the use of two image based techniques – Close-Range Photogrammetry and Image Reasoning – to perform semi-automated tracking of excavation activities. A new image reasoning algorithm, enhanced pattern detection and comparison (EPDC), is introduced to quickly identify changes in poor contrast excavation surfaces. EPDC is illustrated using laboratory and field trials. The proposed image reasoning algorithm paves the way for new uses of large numbers of digital camera and webcam images now available at many construction sites to acquire detailed construction staging information.

Safe Distance between Large-Diameter Rock Pipe Bursting and Nearby Buildings and Buried Structures

Owners of nearby utilities and structures often voice concerns about potential damage to their facilities—particularly during bursting and upsizing of large-diameter pipes in hard rock formations. This paper summarizes analytical and field studies of ground movements and vibrations associated with large-diameter pipe bursting when the pipe trench is in a rock formation. This research involved seven pipe-bursting field experiments in trenches in hard limestone located in Bowling Green, Ohio. Each experiment involved different parameters including trench width, bedding material, bursting system, pipe diameter, and upsize percentage. Ground vibrations and surface and subsurface vertical soil displacements were measured at pre-assigned locations from the pipe centerline. The heave above the pipe centerline turned to settlement as the perpendicular distance increased. The magnitudes of vertical subsurface and surface movements in narrower trenches were higher than were those of wider trenches. The analysis of the ground vibrations indicated that 3.35 m was a safe distance for residential buildings and 2.45 m for nearby buried structures.

Can One Operator Handle Both Water and Wastewater Systems?

To answer the question of whether one operator can handle both the water and wastewater operations at a small water system, the article breaks the problem down into two main areas: financial costs to the customers; and, the regulatory agency's concerns about the potential for cross‐contamination (safety of the supply). The article discusses several options related to the financial issues that include hiring an outside contractor to handle both systems, combining services with a nearby utility, and maintaining your current program. Safety concerns, personal protective equipment, and chlorination of finished water are all discussed.

Utility grid-connected solar photovoltaic power plants for meeting energy needs for rural area in developing countries—A case of India

Abstract Two grid-interactive PV power plants (each 100 kW capacity) are being established in two villages of Uttar Pradesh (India) to meet the vitally needed electrical energy demand of each village and to find additional power to a nearby utility grid. The suitability of such grid connected solar PV power plants are being studied for meeting all the electrical energy need of the unelectrified villages and for the potential of feeding the additional power available from such photovoltaic power plant to a nearby utility grid. At present, the cost of such power plants is very high, around $14.00 per Watt. Such power plants would be very suitable for meeting all the electrical energy needs of rural areas in developing countries when the cost of the PV module and balance of the component will be reduced as a result of development efforts and extension activities going on in the World and in India.