|Overview : |
Purpose of Assignment:
Rehabilitation of the stormwater drainage system at the UN Annex Premises in Rhodespark, Lusaka.
Scope of Works:
The scope of work shall include the following:
- Construction of a soak pit to provide for stormwater disposal.
- Lengthening of the existing stormwater drain channel to meet the design invert level of the drain to the soak pit.
- Removal and reinstallation of motorized gate to facilitate lengthening of drain.
- Replace the existing concrete drainage covers with galvanized steel grating.
- Desilting and thorough cleaning of the existing stormwater drain.
- Correction of the stormwater drain channel slope and concrete repair where necessary.
- Any other works that will restore the structural stability and integrity of the existing stormwater drainage system that are not specifically mentioned in the Scope of Works (SoW) without extra cost to the Client.
The Contractor will be responsible for the following:
- The Contractor shall develop and submit a Construction Method Statement (CMS) for review and approval by UNDP prior to the actual commencement of work. The Construction Method Statement (CMS) shall include the following:
- Construction programme
- Broad plan of the construction works, highlighting the various stages and their context within the whole project
- Details of the Environmental Management Plan, including restricted operations, site access and housekeeping procedures
- Health and Safety (H&S) Management Plan
- Quality Management Plan (QMP)
- Site working hours
- Details of operations likely to result in disturbance, with an indication of the expected duration of each phase with key dates. This should include a procedure for prior notification and relevant statutory and non-statutory (including neighbours) parties so that local arrangements can be agreed upon.
- The Contractor shall provide technical supervision, skilled manpower, tools, equipment and suitable highest quality materials necessary to complete the works.
- The Contractor shall remove existing vegetation only upon approval from the UNDP Facilities Manager.
- The Contractor shall protect sloped areas and the construction in general by installing silt fencing, erosion control matting, wattles, or other protective measures.
- The Contractor shall ensure the unaffected use of the parking area by maintaining a stabilized parking area for all vehicle passing and parking around the construction zones. The contractor shall also sweep the entry roadways whenever construction traffic has deposited soil from the construction site and clean the worksite by the end of each day by dry sweeping paved areas (never wash the soil down storm drains).
- The Contractor shall be responsible for obtaining the necessary and required permits covering the works from state agencies and local units of government.
- The Contractor shall provide as-built drawings of all construction works upon completion.
- The Contractor shall ensure that the materials and workmanship needed to complete the project are of high quality and acceptable to UNDP. All materials whose pot life has expired shall be rejected and removed from the site.
- The Contractor shall be responsible for and comply with standard safety requirements (safety shoes, vest, hard hat, safety harness, lifeline) in working areas; any equipment or work considered dangerous shall be immediately discontinued.
- The Contractor shall carry out testing of the stormwater drainage network and soak pit to make sure it is both functional and water-tight.
- At all stages of the project and after completion, all damaged or altered areas of the premises shall be touched up and restored at the Contractor’s expense. All methods of repair and reinstatement must be acceptable to UNDP.
Delivery, Storage and Protection:
- All materials to be used on-site shall have to be opened and approved in the presence of the UNDP Facilities Manager as per an agreeable consignment quantity before use.
- Products and other materials shall be delivered to the site at such a time as required for proper coordination of the work. The premises has minimal storage space and therefore, cannot make accommodations to store materials for an extended period.
- All equipment and unused material shall be removed at the conclusion of the project; the work area shall at all times be clean and tidy.
- The Contractor shall arrange material storage so as not to interfere with the UNDP’s or other stakeholder’s operations.
- Store all materials in properly protected and dry storage facilities until ready for use; installation of used materials will not be accepted.
- The Contractor shall be responsible for coordinating and receiving all deliveries and shipments.
- The Contractor shall hold UNDP harmless from any loss arising from lost or damaged materials stored at the job site.
- All materials shall be stored in a proper manner protected from natural elements to avoid contamination and deterioration.
- The Contractor shall properly plan for concreting considering the possible locations to station the pump & trucks and waiting area for trucks so as not to interfere with the UNDP’s or other stakeholder’s operations.
- The Contractor shall possess relevant standards and deploy all inspection tools/instruments to carry out the relevant inspections and testing as per relevant standards.
- All concrete works shall strictly comply with standard methods of AASHTO, ASTM or equivalent standards such as British Standards (BS). The Portland cement to be used throughout the works shall be obtained from manufacturers approved in writing and shall be strength class 42.5N or 52.5N to BS EN 197-1. All reinforced concrete works shall strictly comply with BS 8110 or equivalent standards.
- Before ordering cement, the Contractor shall submit details of the proposed supplier for approval before delivery of any material to site.
- Aggregate shall comply with the requirements of BS EN 206 and BS 8500 and shall be of normal weight and from natural sources unless lightweight aggregates are required. Aggregate to be used in the construction of structures for retaining aqueous liquids shall comply with BS 8007, BS 812, BS EN 12620 and BS 882, unless indicated otherwise.
- Sand for mortar shall comply with BS 1199 and BS 1200, or BS EN 13139.
- Water and ice to be used for mixing concrete and mortar shall comply with the requirements of BS EN 1008.
- Reinforcement for use in reinforced concrete shall comply where appropriate with BS 4449, BS 4482, BS 8110 and BS 8666, or ASTM A615. High yield deformed bars shall be Grade B500 complying with BS 4449: 2005, unless otherwise approved. Prior to approval, the Contractor shall provide copies of the manufacturer's certificates of test results relating to the steel reinforcement to be supplied.
- Welded steel wire fabric (“mesh”) reinforcement for use in reinforced concrete shall comply where appropriate with BS 4483, BS 8110 and BS 8666, or ASTM A615.
- Tying wire shall be galvanised mild steel of diameter approximately 1.5 mm. Tying wire shall have the same minimum concrete cover as detailed for reinforcement.
- Before spacers are approved for use in the works, their capability to securely hold the reinforcement in position during concreting without detriment to concrete placement, compaction or durability shall be fully demonstrated. Concrete spacers shall be of similar concrete grade to the parent concrete and shall have non-metallic ties. Concrete spacers shall be provided in accordance with BS 7973.
- Fine finish formwork shall be used for all concrete surfaces unless guided otherwise by the Client’s representative.
- Ordinary polythene sheeting will not entirely constitute a water-proof membrane for surface protection unless approved by UNDP. Polythene sheeting used will normally require 500 gauge in a double layer, or 1,000 gauge.
- Testing of the stormwater drainage network and soak pit to ensure it is both functional and water-tight shall coincide with BS-EN-752:2008.
- Water to be used for curing concrete and mortar shall be fresh (“potable”) water, subject to the same requirements as mixing water.
- At least 24 hours’ notice shall be given by the Contractor to the UNDP Facilities Manager of the intention to place concrete.
- All work shall be done by thoroughly qualified personnel in a neat and workmanlike manner. All work that shows carelessness or lack of skill in execution or is defective due to any other cause will be rejected and corrected at the Contractor’s expense. Said work shall be redone to the satisfaction of UNDP prior to acceptance of work.
The contract further guarantees that if, during a period of one year from the date of the certificate of practical completion any such defects will be repaired by the contractor at his own cost. The Contractor shall also carry out a second desilting and thorough cleaning of the existing stormwater drain before the onset of the 2022 rainy season.