SEEDS) Sustainability Program Student Research Report
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UBC Social Ecological Economic Development Studies (SEEDS) Sustainability Program Student Research Report Replacement of the Spiral Drain at the North End of UBC Campus Mona Dahir, Jas Gill, Danny Hsieh, Rachel Jackson, Michael Louws, Chris Vibe University of British Columbia CIVL 446 April 7th, 2017 Disclaimer: “UBC SEEDS Sustainability Program provides students with the opportunity to share the findings of their studies, as well as their opinions, conclusions and recommendations with the UBC community. The reader should bear in mind that this is a student research project/report and is not an official document of UBC. Furthermore, readers should bear in mind that these reports may not reflect the current status of activities at UBC. We urge you to contact the research persons mentioned in a report or the SEEDS Sustainability Program representative about the current status of the subject matter of a project/report”. UBC NORTH CAMPUS SPIRAL DRAIN REPLACEMENT Final Design Report PREPARED FOR: Client Representative: Mr. Doug Doyle, P.Eng Associate Director, Infrastructure and Planning Client: UBC Social Ecological Economic Development Studies (SEEDS) Project Team 24: Rachel Jackson Danny Hsieh Mona Dahir Michael Louws Jasninder Gill Chris Vibe April 7th, 2017 Executive Summary Vortex Consulting has prepared a detailed design report, as requested by UBC Social, Ecological, Economic Development Studies (SEEDS), for the replacement of UBC's current North Campus Stormwater Management facility, the spiral drain. This report intends to provide UBC SEEDS with an understanding of the design components, technical analysis and design, and project costs and construction sequencing, that are required to mitigate a 1 in 200 year storm event. The main objective of this project is to design a replacement for the spiral drain structure that can withstand the rainfall loading of a 200 year storm. The potential for significant damage due to flooding in the event of a 1 in 200 year storm is significant, both to sensitive local ecosystems (ex. the cliffs near MOA), as well as UBC assets in the area. Due to the lifespan and design limitations of the existing spiral drain, a new replacement will be required for UBC north campus. Secondary objectives such as optimizing economics, sustainability and constructability are outlined in the report. Vortex Consulting has established the following design solution with three main components; a Detention Tank that stores storm event rainfall and releases at a controlled rate, a Baffle Drop Structure to transport and dissipate the energy of water as travels 60 meters vertically, and a Horizontal Shaft and Outfall to transport water to the outfall located on Tower Beach. With a design life of 100 years, the initial capital costs are estimated to be $9,552,226 and the project will be completed by September 20th, 2017 with a May 1st, 2017 start date. 1 Table of Contents Executive Summary ....................................................................................................................................... 1 List of Illustrations ......................................................................................................................................... 5 1.0 Introduction ............................................................................................................................................ 6 2.0 Project Description .................................................................................................................................. 8 2.1 Project Scope and Objectives .............................................................................................................. 8 2.2 Site Overview and Hydrological Background ...................................................................................... 9 2.3 Key Issues & Constraints ..................................................................................................................... 9 3.0 Design Overview and Specifications ..................................................................................................... 10 3.1 Layout and Design Components ....................................................................................................... 10 3.2 Detention Tank.................................................................................................................................. 11 3.3 Baffle Drop Structure ........................................................................................................................ 12 3.4 Horizontal Shaft & Outfall Pipe ......................................................................................................... 13 3.5 Stormwater Re-routing ..................................................................................................................... 15 4.0 Design Inputs......................................................................................................................................... 17 4.1 Adopted Design Life & Maintenance ................................................................................................ 17 4.2 Design Loads ..................................................................................................................................... 17 4.3 Technical Design Parameters & Standards ....................................................................................... 18 4.4 Software Package .............................................................................................................................. 18 4.4.1 EPA-SWMM ................................................................................................................................ 19 4.4.2 AutoCAD, Revit and Sketchup .................................................................................................... 19 4.4.3 SAP2000 ..................................................................................................................................... 19 4.4.4 Plaxis 2D ..................................................................................................................................... 19 5.0 Technical Design and Analysis............................................................................................................... 21 5.1 Hydrotechnical .................................................................................................................................. 21 5.1.1 Design Storm .............................................................................................................................. 21 5.1.2 SWMM Modelling ...................................................................................................................... 22 5.1.3 System Volume and Flow Demands ........................................................................................... 22 5.2 Structural........................................................................................................................................... 22 5.3 Geotechnical ..................................................................................................................................... 23 5.3.1 Site Description .......................................................................................................................... 23 2 5.3.2 Area Geology and Subsoil Conditions ........................................................................................ 24 5.3.3 Design Groundwater level ......................................................................................................... 25 5.3.4 Slope Stability ............................................................................................................................. 25 5.3.5 Recommendations for Site Investigation ................................................................................... 26 5.4 Environmental Impact ....................................................................................................................... 27 5.4.1 Water Quality ............................................................................................................................. 29 5.4.2 Erosion Control .......................................................................................................................... 29 5.5 Constructability of Design ................................................................................................................. 29 5.5.1 Baffle Drop Shaft ........................................................................................................................ 29 5.5.2 Horizontal Shaft ......................................................................................................................... 30 5.5.3 Detention Tank ........................................................................................................................... 30 6.0 Construction Drawings and Plans ......................................................................................................... 31 7.0 Construction Work Plan ........................................................................................................................ 32 7.1 Construction Methodology ............................................................................................................... 32 7.1.1 Detention Tank ........................................................................................................................... 32 7.1.2 Baffle Drop Shaft .......................................................................................................................