Construction and supply of reinforced concrete manholes

Oxfam is a global movement of people, working together to end the injustice of poverty. Oxfam has been working in Lebanon since 1993. We provide humanitarian assistance to vulnerable people affected by conflict, and we promote economic justice and good governance, and women’s rights. Oxfam also works with local partners to contribute to the protection and empowerment of marginalized women and men.

The works are in Qsaybeh and involve the urgent rehabilitation of manholes. The contractor is expected to provide all materials and labor necessary for the construction or rehabilitation. The existing pipelines are live and contain water, and the contractor shall take all necessary precautions to safely work around them while maintaining system operation. The works are to be executed without asphalt surfacing and without pipelaying, as the municipality will carry out the road asphalting after completion of the construction. All materials and workmanship must comply with Oxfam’s technical requirements and the supervising engineer’s approval.

1. General Tasks

• Mobilization of workforce, equipment, and materials to the site.
• Site preparation including excavation, minor demolition, and temporary facilities as required.
• Demobilization and clearance of the site upon completion of works.
• Supply and installation of an approved project information board.

2.Reinforced Concrete Manhole Construction

The contractor shall construct a reinforced concrete manhole with internal dimensions of:

• 1mx1mx1m
• 1mx1mx0.8m
• 0.6mx0.6mx0.6m
• 0.4mx0.4mx0.5m
• 0.8mx0.8mx0.6m  
• 1.2mx1mx1m
• 1mx0.8mx0.8m

The manhole shall be casted in-situ using C25 grade concrete. Dimensions shall be confirmed on site and approved by the Engineer.

Cast-in-Situ Construction:

• The base slab shall of 20cm thick and walls of 15cm thick.
• Single-layer steel reinforcement shall be provided in all vertical and horizontal elements, with adequate concrete cover. Reinforcement shall be properly tied, positioned, and supported to maintain alignment during concrete placement. (T12 at 20 cm in two directions, modifiable upon request.)
• The base slab shall rest on a well-compacted subgrade, and all formworks shall be rigid, properly aligned, and treated with an approved release agent.

General Requirements:

• All pipe penetrations shall be sealed using non-shrink grout or flexible pipe sleeves to ensure watertightness.
• Internal surfaces of the manhole shall be smooth, uniform, and free from honeycombing or segregation.
• A reinforced concrete cover slab shall be installed over the chamber, designed to withstand heavy vehicular traffic according to the applicable road loading class.
• The cover slab shall include an access opening fitted with a heavy-duty steel sheet manhole cover and frame, suitable for roads subjected to heavy traffic.

Completion:

• After construction, the manhole chamber shall be cleaned, and the surrounding trench shall be backfilled in compacted layers with suitable material.
• The surface shall be reinstated to match existing conditions or as directed by the Engineer.

The exact location of the manholes will be specified by SLWE and Oxfam.

1. Steel Sheet Manhole Cover 5mm

Supply, Delivery, and Installation of Steel Sheet Manhole Cover with Copper Lock and Hinge

The contractor shall supply, deliver, and install a steel sheet manhole cover and frame to fit the dimensions of each manhole opening. The cover shall be fabricated from high-quality mild steel plates of adequate thickness (5 mm) to ensure durability and sufficient load-bearing capacity. The cover shall be properly supported by steel beams underneath to minimize deflection and ensure structural stability under load.

All parts shall be coated with anti-corrosive paint to prevent rust and corrosion.

The cover shall be equipped with a copper lock and suitable hinge, ensuring secure closure while allowing easy opening and closing.

See attached photo below at the end of this document for reference.

4. Supply, Delivery, and Installation of Valve Box (Bouche à Clé)

The contractor shall supply, deliver, and install a Bouche à Clé (valve box) with a diameter of 4 inches. The valve box shall be durable, compatible with the installed valves

5.-Supply, Delivery, and Installation of Heavy-Duty Copper Gate Valves

The contractor shall supply, deliver, and install heavy-duty copper gate valves of sizes 2-inch, 3-inch, and 4-inch (EU Origin or equivalent), including all necessary unions, flanges, fixings, and accessories required for proper operation. All valves shall be durable, fully functional, and compatible with the existing system. Installation shall ensure leak-free connections and compliance with the Engineer’s specifications and alignment requirements.

6. Additional Supplier Obligations:

• The contractor shall take into consideration that the dimensions of manholes, covers, and other components may vary on site due to actual conditions encountered during construction. The contractor is responsible for adjusting and accommodating any dimensional differences while ensuring full compliance with design requirements, and functional performance. All adjustments shall be coordinated with and approved by the Oxfam’s Engineer prior to execution.
• The Consultant shall be fully responsible for any damages caused during the execution of the works and shall rehabilitate or restore the affected areas to their original condition at no additional cost
• The supplier’s relationship will be directly with Oxfam staff.
• Oxfam staff will be responsible for inspecting and confirming the delivery and completion of the project.
• The supplier shall submit comprehensive datasheets meeting all minimum requirements.
• Oxfam reserves the right to increase or decrease quantities at the same unit cost.
• Any item not complying with the technical specifications will be rejected.
• Oxfam will inform the supplier of the exact date for project implementation and delivery.

• Submission instructions

  Quotations and applications must reach Oxfam no later than 4 November 2025, midnight Lebanon time.

  Responses must be submitted in English, electronically or by hand to: lebanonprocurement@oxfam.org.uk

  The subject of the mail should be Construction and supply of reinforced concrete manholes + [Name of bidder]

  Any questions, remarks or requests for clarification can be sent up to 4 days before the submission deadline in writing. The (anonymised) questions will be answered to all applicants.