Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
Effective Use of an Underdrain System in Construction on Expansive Subsoils
This paper examines the practice of geotechnical engineers and design and construction professionals of construction on expansive soil and bedrock in the Colorado Front Range. A common practice is to support structures on deep foundations, generally drilled piers and place slab on grade. Over-excavation of expansive subsoils below the structures is recommended to mitigate the effect of swelling subsoils. Over-excavation creates a bathtub, which stores water and results in the creation of a perched groundwater condition. This paper contends that the perched groundwater is more from the interruption of historic flow through the upper bedrock permeable zones than the factors commonly associated with this phenomenon, such as inadequate grading, use of water subsequent to the development, etc. The measurements conducted in the sump pits and discharge from the pumps indicates steady flow of water during all times of the year. This condition should be recognized and steps taken to drain the water by use of a properly-designed underdrain system. Continuing movement and distress is experienced in many existing structures constructed on expansive subsoils. A deep underdrain system (DUS) is effective in intercepting the flow of groundwater and preventing the development of perched groundwater, which provides moisture to the underlying expansive subsoils and causes continued movement and distress. This paper presents cases where the use of a deep underdrain system has prevented the continuing movement and distress of the existing structures. Measurements conducted of groundwater flow in the sump pits confirm the effectiveness of the system. The geology and hydrogeology of the Denver Formation indicates flow of groundwater through the permeable zones in the upper portion of bedrock. The author contends that the flow pattern in the upper bedrock has a significant effect in wetting the subsoils and should be recognized and considered in evaluation of the depth of wetting in this area.
Effective Use of an Underdrain System in Construction on Expansive Subsoils
This paper examines the practice of geotechnical engineers and design and construction professionals of construction on expansive soil and bedrock in the Colorado Front Range. A common practice is to support structures on deep foundations, generally drilled piers and place slab on grade. Over-excavation of expansive subsoils below the structures is recommended to mitigate the effect of swelling subsoils. Over-excavation creates a bathtub, which stores water and results in the creation of a perched groundwater condition. This paper contends that the perched groundwater is more from the interruption of historic flow through the upper bedrock permeable zones than the factors commonly associated with this phenomenon, such as inadequate grading, use of water subsequent to the development, etc. The measurements conducted in the sump pits and discharge from the pumps indicates steady flow of water during all times of the year. This condition should be recognized and steps taken to drain the water by use of a properly-designed underdrain system. Continuing movement and distress is experienced in many existing structures constructed on expansive subsoils. A deep underdrain system (DUS) is effective in intercepting the flow of groundwater and preventing the development of perched groundwater, which provides moisture to the underlying expansive subsoils and causes continued movement and distress. This paper presents cases where the use of a deep underdrain system has prevented the continuing movement and distress of the existing structures. Measurements conducted of groundwater flow in the sump pits confirm the effectiveness of the system. The geology and hydrogeology of the Denver Formation indicates flow of groundwater through the permeable zones in the upper portion of bedrock. The author contends that the flow pattern in the upper bedrock has a significant effect in wetting the subsoils and should be recognized and considered in evaluation of the depth of wetting in this area.
Effective Use of an Underdrain System in Construction on Expansive Subsoils
Kumar, Narender (Autor:in)
Biennial Geotechical Seminar 2012 ; 2012 ; Denver, Colorado, United States
GeoChallenges ; 164-177
09.11.2012
Aufsatz (Konferenz)
Elektronische Ressource
Englisch
Underdrain drainage system, underdrain construction method and application
| Europäisches Patentamt | 2023