Agenda - Public Works Committee - 08/15/2011

Home

APPENDIX E Exception: Drainage facilities and terracing need not be provided where the ground slope is not steeper than 3 hori- zontal to 1 vertical (33 percent). J109.2 Terraces. Terraces at least 6 feet (1829 mm) in width shall be established at not more than 30 -foot {9144 mm) verti- cal intervals on all cut or fill slopes to control surface drainage and debris. Suitable access shall be provided to allow for clean- ing and maintenance. Where more than two terraces are required, one terrace, located at approximately mid- height, shall be at least 12 feet (3658 mm) in width. Swales or ditches shall be provided on terraces. They shall have a minimum gradient of 20 horizontal to 1 vertical (5 per- cent) and shall be paved with concrete not less than 3 inches (76 mm) in thickness, or with other materials suitable to the appli- cation. They shall have a minimum depth of 12 inches (305 mm) and a minimum width of 5 feet (1524 mm) A single run of swale or ditch shall not collect runoff from a tributary area exceeding 13,500 square feet (1256 m (pro- jected) without discharging into a down drain. J109.3 Interceptor drains. Interceptor drains shall be installed along the top of cut slopes receiving drainage from a tributary width greater than 40 feet (12 192 mm), measured horizontally. They shall have a minimum depth of 1 foot (305 mm) and a minimum width of 3 feet (915 mm) The slope shall be approved by the building official, but shall not be less than 50 horizontal to 1 vertical (2 percent). The drain shall be paved with concrete not less than 3 inches (76 mm) in thickness, or by other materials suitable to the application. Discharge from the drain shall be accomplished in a manner to prevent erosion and shall be approved by the building official. J109.4 Drainage across property lines. Drainage across property lines shall not exceed that which existed prior to grad- ing. Excess or concentrated drainage shall be contained on site or directed to an approved drainage facility. Erosion of the ground in the area of discharge shall be prevented by installa- tion of nonerosive down drains or other devices. SECTION J110 EROSION CONTROL J110.1 General. The faces of cut and fill slopes shall be pre- pared and maintained to control erosion. This control shall be permitted to consist of effective planting. Exception: Erosion control measures need not be provided on cut slopes not subject to erosion due to the erosion- resis- tant character of the materials. Erosion control for the slopes shall be installed as soon as practicable and prior to calling for final inspection. J110.2 Other devices. Where necessary, check dams, crib- bing, riprap or other devices or methods shall be employed to control erosion and provide safety. ASTM D 1557 -e01 SECTION J111 REFERENCED STANDARDS Test Method for Laboratory Compaction Characteristics of Soil Using Modified Effort [56,000 ft- lb /ft (2,700kN- m/m 1107.6 628 2007 MINNESOTA STATE BUILDING CODE