Handling and Installation Instructions

Transcription

1 Handling and Installation Instructions SUPERTANK Water Reclamation Solutions, LLC

2 Unloading and Handling NOTE: It is the responsibility of the installer to follow OSHA safety guidelines during the installation, handling, and usage of all WRS products. Although the WRS SUPERTANK will withstand normal handling it should be handled with reasonable care. Dragging the pipe at any time will damage the coatings. Avoid striking rocks or hard objects when lowering pipe into trenches. Since corrugated steel pipes are relatively light weight, they can be handled with light equipment. Use of slings is recommended to properly handle the pipe. Forked equipment is acceptable if care is taken to protect the tank coatings from abrasion by the forks. If the TrenchCoat is damaged during the handling or installation process, contact WRS to purchase DOW approved TrenchCoat repair compound. The SUPERTANK must never be dumped directly from a truck bed while unloading. Whenever transporting and handling the WRS SUPERTANK, belts or straps should be used rather than chains. Padding should also be used between the pipe and the trailer bed, racks, blocks, or other hard objects (old carpet works well). If chains must be used, padding the chains will help minimize any damage. Once lifted from the trailer, the SUPERTANK should be carefully placed on timbers to protect the flanges from bearing the weight of the tank during storage. Rolling the pipe off the trailer is strongly discouraged. During placement of the pipe, belts or straps should be used. If chains must be used, padding the chains will help to minimize any damage. (see fig. 1) Care should be exercised during backfilling to prevent dumping of large aggregate material onto the SUPERTANK. Protect the SUPERTANK surface and prevent large stone from falling on the pipe. Backfill immediately next to the pipe should be compacted by hand-operated methods. Figure 1

3 Installation and Backfill Foundation Preparation NOTE: It is the responsibility of the purchaser to follow OSHA safety guidelines during the installation, handling, and usage of all WRS products 1. Begin excavation only when installation of SUPER TANK can immediately follow 2. If native soils do not provide proper resistance and support to the structural backfill and compactive efforts of installation, remove the poor soils down to a suitable depth and width replacing poor native material with suitable structural backfill material. Migration of fines from the native soil trench to the structural backfill should be avoided. A non-woven filter fabric should be used to line the trench if soil migration is a concern. 3. At least 6 of structural backfill material should be used for bedding. It should be graded into a smooth, uniform base which will support the design load. Above that, a shaped bed should be created to support the body of the SUPERTANK and relieving undo force on the flanges as well as ease the placement of haunch backfill material. (see fig. 2) In the alternative, a small trench may be dug in the area of the flanges. The body of the SUPERTANK should be fully supported before any load is placed on the flanges in any case. 4. Trench width shall be one Tank Diameter plus enough space on each side for walk behind vibratory compaction equipment OR the width required by OSHA safety regulations. Whichever is greater. 5. If a pipe anchoring system is required, the helical pipe anchors (supplied by WRS) should be installed (but not the pipe straps) before the structural backfill to facilitate ease of installation. 6. If an underdrain system is designed it should be installed as the bedding is being placed or immediately thereafter depending on invert elevation of the underdrain. A properly formed foundation cradle can save compactive effort later, especially in the haunch area. 7. Never install the SUPERTANK on bed of sod, frozen earth or on a bed that contains large boulders or rock. Figure 2

4 Placement and Backfill NOTE: It is the responsibility of the purchaser to follow OSHA safety guidelines during the installation, handling, and usage of all WRS products. 1. Pipe should be handled and moved as shown in the WRS handling instructions. 2. If more than one SUPERTANK unit is being installed, consult WRS lay schedule and match marks on each unit to be sure units are laid out as intended for maximum joint performance and ease of installation. Skipping this necessary step will produce a poor installation. 3. Pipe should be place on a cradle of structural backfill which has been prepared before setting of each unit. Sufficient space should be left in each cradle to accommodate flanges on the end of each SUPERTANK unit. In the alternative, a small trench may be dug in the area of the flanges. In any case, no load should be placed on the flanges until the body of the tank is fully supported. 4. Check alignment of stub and manhole risers to be sure they fall in the proper location, orientation, and angle before proceeding. 5. If multiple units are being installed, apply joint sealant supplied by WRS to flanged joints. Align bolt holes and slip bolts through the holes. Apply nuts and washers and hand tighten. 6. Recheck alignment of tanks, stubs, and manhole risers before proceeding. (single units will arrive at the jobsite pre-assembled) 7. Tighten Flange bolts to 160 ft-lbs of torque. 8. Begin placing backfill. Use 8-inch loose lifts and compact to 90% AASHTO T99 standard proctor density. Lifts of backfill must be placed in a balanced manner. No more than a one lift differential between each side of the pipe is allowable. (see fig. 3) Placing lifts of backfill equally on both sides of the Tank will help prevent shape distortion during installation Figure 3 9. Compact each lift to a 90% proctor density using walk behind vibratory compactors. If a self locking stone is used (eg. #57), vibratory compaction is necessary only at the installers discretion to eliminate settling.

5 10. Continue until minimum cover depth is reached. (minimum cover varies depending on diameter, load, and gauge of tank) Acceptable Backfill Materials Backfill material shall be drainable, angular, well graded, manufactured aggregate. AASHTO Classes A-1, A-2, or A-3 may also be acceptable. Maximum particle size shall be 1.5. Adequate local materials may be used upon approval of a soils engineer. 1. Class I - Angular, one quarter to one and one half (1/4 to 1-1/2") inch graded stone, including a number of fill materials that have regional significance such as coral, slag, cinders, crushed stone, and crushed shells. Well graded, angular aggregates often require less effort to achieve 90%SPD 2. Class II - Coarse sands and gravels with maximum particle size of one and one half (1-1/2") inch, including variously graded sands and gravels containing small percentages of fines, generally granular and non-cohesive, either wet or dry. Soil Types GW, GP, SW, and SP (Unified Soil Classification System) are included in this class. 3. Class III - Fine sand and clayey gravels, including fine sands, sand-clay mixtures, and gravel-clay mixtures. Soil Types GM, GC, SM, and SC (Unified Soil Classification System) are included in this class. All materials must be free from sod, frozen earth or large rocks. Backfill materials must be adequately dried so as to allow compaction to 90% standard proctor density. Agency Installation Specifications Reference AASHTO Standard Specifications for Highway Bridges-Division II, Section 26 ASTM Standard Practice for Installing Factory Made Corrugated Steel Pipe for Sewers and Other Applications - ASTM A798 AREMA Manual for Railway Engineering - Section 4.12 USDA - Natural Resources Conservation Service U.S. Dept. of Agriculture Forest Service Construction Specification Section 51 Paragraph 6 Specification for Construction of Roads and Bridges, Section through Federal Lands Highway FP92 Section , , , and

6 Construction Loading Minimum cover as designed for a project refers to the minimum cover over the top of a structure of Structural backfill needed for AASHTO H20 loading conditions. Construction loads frequently exceed these conditions and necessitate mitigation during the construction process. One method of easing the impact of construction loading is to add increased minimum cover during the construction process. The installer should be aware of their responsibility to take great care to avoid over loading underground structures with off road construction vehicles. Calculations concerning construction loads should take into account the full loading of that vehicle or equipment while in use. Tracked vehicles place less point load on an underground structure than wheeled vehicles of the same weight. This becomes of particular interest in projects which involve parallel installations of underground structures thus stretching the limits of reach of most excavators, cranes and the like. Further, fully loaded construction equipment tends to create ruts in the road surface as they turn, load, and haul. This can have a serious and detrimental effect on the intended minimum cover and the structural below. Special care should be taken to compensate for this rutting action. Minimum Cover Guidelines for off-road construction Equipment Pipe Diameter in Inches Minimum Cover (ft.) for Indicated Axle Loads (kips)