Okaloosa County BOCC — February 18, 2014 — Underground Electric Manhole — reading text

and other excavations. DEWATERING DATE: 9/16/2013 OKALOOSA COUNTY WATER AND SEWER 02240 - 4 SECTION 02240 Russell Stephenson - Electrical Manhole Rehabilitation DEWATERING 1. Maintain piezometric water level a minimum of 24 inches below surface of excavation. E. Dispose of water removed by dewatering in a manner that avoids endangering public health, property, and portions of work under construction or completed. Dispose of water and sediment in a manner that avoids inconvenience to others. Provide sumps, sedimentation tanks, and other flow-control devices as required by authorities having jurisdiction. F. Provide standby equipment on site, installed and available for immediate operation, to maintain dewatering on continuous basis if any part of system becomes inadequate or fails. If dewatering requirements are not satisfied due to inadequacy or failure of dewatering system, restore damaged structures and foundation soils at no additional expense to Owner. 1. Remove dewatering system from Project site on completion of dewatering. Plug or fill well holes with sand or cut off and cap wells a minimum of 36 inches below overlying construction. G. Damages: Promptly repair damages to adjacent facilities caused by dewatering operations. 3.3 FIELD QUALITY CONTROL A. Observation Wells: Provide, take measurements, and maintain at least the minimum number of observation wells or piezometers indicated; additional observation wells may be required by authorities having jurisdiction. 1. Observe and record daily elevation of ground water and piezometric water levels in observation wells. 2. Repair or replace, within 24 hours, observation wells that become inactive, damaged, or destroyed. In areas where observation wells are not functioning properly, suspend construction activities until reliable observations can be made. Add or remove water from observation-well risers to demonstrate that observation wells are functioning properly. 3, Fill observation wells, remove piezometers, and fill holes when dewatering is completed. B. Provide continual observation to ensure that subsurface soils are not being removed by the dewatering operation. END OF SECTION 02240 DEWATERING DATE: 9/16/2013 OKALOOSA COUNTY WATER AND SEWER 02240 - 5 SECTION 02240 Russell Stephenson - Electrical Manhole Rehabilitation DEWATERING (THIS PAGE INTENTIONALLY LEFT BLANK) DEWATERING DATE: 9/16/2013 OKALOOSA COUNTY WATER AND SEWER 02240 - 6 SECTION 02260 EXCAVATION SUPPORT & PROTECTION SECTION 02260 EXCAVATION SUPPORT & PROTECTION PART 1 - GENERAL 1.1 RELATED DOCUMENTS A. Drawings and general provisions of the Contract, including General and Supplementary Conditions and Division 01 Specification Sections, apply to this Section. 1.2 SUMMARY A. Section includes temporary excavation support and protection systems. B. Related Sections: 1. oe Section 01320 "Construction Progress Documentation" and Section 01322 "Photographic Documentation" for recording preexisting conditions and excavation support and protection system progress. Section 01500 "Temporary Facilities and Controls" for temporary utilities and support facilities. Section 02240 "Dewatering" for dewatering system for excavations. 1.3 PERFORMANCE REQUIREMENTS A. Design, furnish, install, monitor, and maintain excavation support and protection system capable of supporting excavation sidewalls and of resisting soil and hydrostatic pressure and superimposed and construction loads. 1. Delegated Design: Design excavation support and protection system, including comprehensive engineering analysis by a qualified professional engineer, using performance requirements and design criteria indicated. 2. Prevent surface water from entering excavations by grading, dikes, or other means. 3. Install excavation support and protection systems without damaging existing buildings, structures, and site improvements adjacent to excavation. 4. Monitor vibrations, settlements, and movements. EXCAVATION SUPPORT AND PROTECTION Date: 9/16/2013 OKALOOSA COUNTY WATER AND SEWER 02260 - 1 SECTION 02260 Russell Stevenson - Electrical Manhole Rehabilitation EXCAVATION SUPPORT & PROTECTION 1.4 A. 1.5 1.6 SUBMITTALS Shop Drawings: For excavation support and protection system. Delegated-Design Submittal: For excavation support and protection system indicated to comply with performance requirements and design criteria, including analysis data signed and sealed by the qualified professional engineer responsible for their preparation. Qualification Data: For qualified professional engineer licensed in the State of Florida, with experience designing shoring and supports structures for deep coastal excavations with high groundwater. Other Informational Submittals: 1. Documentation: Photograph or video existing conditions of adjacent construction and site improvements that might be misconstrued as damage caused by the absence of, the installation of, or the performance of excavation support and protection systems. Submit before Work begins. 2. Record Drawings: Identifying and locating capped utilities and other subsurface structural, electrical, or mechanical conditions prior to installation of sheeting. a. Note locations and capping depth of wells and well points. QUALITY ASSURANCE Pre-installation Conference: Conduct conference at Project site. 1. Review methods and procedures related to excavation support and protection system including, but not limited to, the following: Geotechnical report. Existing utilities and subsurface conditions. Proposed excavations. Proposed equipment. Monitoring of excavation support and protection system. Working area location and stability. Coordination with waterproofing. Abandonment or removal of excavation support and protection system. sa mono oe PROJECT CONDITIONS Interruption of Existing Utilities: Do not interrupt any utility serving facilities occupied by Owner or others unless permitted under the following conditions and then only after arranging to provide temporary utility according to requirements indicated: EXCAVATION SUPPORT AND PROTECTION DATE: 9/16/2013 OKALOOSA COUNTY WATER AND SEWER 02260 - 2 SECTION 02260 Russell Stevenson - Electrical Manhole Rehabilitation EXCAVATION SUPPORT & PROTECTION 1. Notify the Construction Manager and Owner no fewer than two days in advance of proposed interruption of utility. 2. Do not proceed with interruption of utility without Construction Manager's written permission. B. Project-Site Information: A geotechnical report has been prepared for this Project and is available for information only. The opinions expressed in this report are those of geotechnical engineer and represent interpretations of subsoil conditions, tests, and results of analyses conducted by geotechnical engineer. Owner will not be responsible for interpretations or conclusions drawn from the data. 1. Make additional test borings and conduct other exploratory operations necessary for excavation support and protection. 2. The geotechnical report is included elsewhere in the Project Manual. C. Survey Work: Survey adjacent existing buildings, structures, and site improvements; establish exact elevations at fixed points to act as benchmarks. Clearly identify benchmarks and record existing elevations. 1. During installation of excavation support and protection systems, regularly resurvey benchmarks, maintaining an accurate log of surveyed elevations and positions for comparison with original elevations and positions. Promptly notify Construction Manager if changes in elevations or positions occur or if cracks, sags, or other damage is evident in adjacent construction. PART 2 - PRODUCTS 2.1 MATERIALS A. General: Provide materials that are either new or in serviceable condition. B. — Structural Steel: ASTM A 36/A 36M, ASTM A 690/A 690M, or ASTM A 992/A 992M. C. Steel Sheet Piling: ASTM A 328/A 328M, ASTM A 572/A 572M, © or ASTM A 690/A 690M; with continuous interlocks. 1. Corners: Roll-formed corner shape with continuous interlock. D. Wood Lagging: Lumber, mixed hardwood, nominal rough thickness of size and strength required for application. E. Shotcrete: Comply with Section 033713 "Shotcrete" for shotcrete materials and mixes, reinforcement, and shotcrete application. EXCAVATION SUPPORT AND PROTECTION DATE: 9/16/2013 OKALOOSA COUNTY WATER AND SEWER 02260 - 3 SECTION 02260 Russell Stevenson - Electrical Manhole Rehabilitation EXCAVATION SUPPORT & PROTECTION F. G. H. I. Cast-in-Place Concrete: ACI 301, of compressive strength required for application. Reinforcing Bars: ASTM A 615/A 615M, Grade 60, deformed. Tiebacks: Steel bars, ASTM A 722/A 722M. Tiebacks: Steel strand, ASTM A 416/A 416M. PART 3 - EXECUTION 3.1 A. 3.2 PREPARATION Protect structures, utilities, sidewalks, pavements, and other facilities from damage caused by settlement, lateral movement, undermining, washout, and other hazards that could develop during excavation support and protection system operations. 1. Shore, support, and protect utilities encountered. Install excavation support and protection systems to ensure minimum interference with roads, streets, walks, and other adjacent occupied and used facilities. 1. Do not close or obstruct streets, walks, or other adjacent occupied or used facilities without permission from Owner and authorities having jurisdiction. Provide alternate routes around closed or obstructed traffic ways if required by authorities having jurisdiction. Locate excavation support and protection systems clear of permanent construction so that forming and finishing of concrete surfaces are not impeded. Monitor excavation support and protection systems daily during excavation progress and for as long as excavation remains open. Promptly correct bulges, breakage, or other evidence of movement to ensure that excavation support and protection systems remain stable. Promptly repair damages to adjacent facilities caused by installing excavation support and protection systems. SHEET PILING Before starting excavation, install one-piece sheet piling lengths and tightly interlock to form a continuous barrier. Accurately place the piling, using templates and guide frames unless otherwise recommended in writing by the sheet piling manufacturer. Limit vertical offset of adjacent sheet piling to 60 inches. Accurately align exposed faces of sheet piling to vary not more than 2 inches from a horizontal line and not more EXCAVATION SUPPORT AND PROTECTION DATE: 9/16/2013 OKALOOSA COUNTY WATER AND SEWER 02260 - 4 SECTION 02260 Russell Stevenson - Electrical Manhole Rehabilitation EXCAVATION SUPPORT & PROTECTION than 1:120 out of vertical alignment. Cut tops of sheet piling to uniform elevation at top of excavation. 3.3 TIEBACKS A. Tiebacks: Drill, install, grout, and tension tiebacks. Test load-carrying capacity of each tieback and replace and retest deficient tiebacks. 1. Test loading shall be observed by a qualified professional engineer responsible for design of excavation support and protection system. 2. Maintain tiebacks in place until permanent construction is able to withstand lateral soil and hydrostatic pressures. 3.4 BRACING A. Bracing: Locate bracing to clear columns, floor framing construction, and other permanent work. If necessary to move brace, install new bracing before removing original brace. 1. Do not place bracing where it will be cast into or included in permanent concrete work unless otherwise approved by Architect. 2. Install internal bracing, if required, to prevent spreading or distortion of braced frames. 3. Maintain bracing until structural elements are supported by other bracing or until permanent construction is able to withstand lateral earth and hydrostatic pressures. 3.5 REMOVAL AND REPAIRS A. Remove excavation support and protection systems when construction has progressed sufficiently to support excavation and bear soil and