DSC for Tunnel Construction – EPTISA

Melamchi water supply project includes mainly of 2 components, i.e. infrastructure development and social and environmental support. Hence as a Project Engineer, the role of DSC is to supervise all activities running under these components while implementation of different project activities.

Infrastructure development mainly refers the construction of Melamchi Diversion Scheme (MDS) and water treatment plant (WTP) so there are different DSCs in order to monitor the MDS activities and the WTP.

DSCs Scope of Work for MDS

MDS includes diversion weir, intake, settling basins, river training works and about 26.5 km of diversion tunnel, and a short pipeline from the downstream portal to the water treatment plant. The Consultant shall act in capacity as the “Engineer” and represent the Client in the tunnel contract that is based on the FIDIC “Condition of Contract for Construction for Building and Engineering Works (Designed by the Client), Multi Lateral Development Bank Harmonised Edition March 2006”. The Engineer shall have the full responsibility for the professional quality and sufficiency of the supervision with respect to progress, quality of materials and work, measurements of quantities, costs, and legal aspects related to the contracts.

In addition to the supervision tasks defined above, the Consultant shall also carry out the detailed design based on the tender design.
DSC shall furthermore provide intermittent inputs in the evaluation of bids as well as contract negotiations. The Consultant shall also develop a comprehensive “Project Construction Supervision Manual” within 2 months of the commencement of the supervision services. More systematically DSCs task and responsibility can be described as:

I. Overall Design and Supervision

Detailed Design – The detailed design has to be developed into a detailed design which requires completely defining of the content of the tunnel contract package. To define the necessary works for the detailed design documents, a design review is be performed at the start of the design works. This design review shall enable the DSC to adopt previous design phases. A respective design review report will be worked out which reviews, checks and comments the previous design phases as well as define necessary additional work for the detailed design.

Supervision -The supervision service covers the tunnel contract (Contract No. -MDS/DT/01), comprising the following main components:

Construction camps at Ambathan, Gyalthum, Sindhu and Melamchi Pul Bazar, including water supply, sanitation, etc.,
Adits at Ambathan, Gyalthum and Sindhu, tunnel 12.7m2 to 18.4 m² cross sectional area and length approx. 26 km, chainage 0+000 to 26+500
Tunnel flushing system at Ambathan adit
Headworks and river training and intake at Ribarma with de-sanding basin.
Headworks hydraulic steelwork supply and construction.
Construction camp at Sundarijal, including water supply, sanitation, etc.,
Pipeline of diameter 1.6 m from tunnel portal to WTP, length 255m
Gate valve arrangement at portal and spillway/bypass flushing system to Bagmati River, other control works at downstream and Portal at Sundarijal
Maintance of access roads.

Other important components to be supervised are:

Spoil tips and quarries
Environmental management and
Maintenance of existing roads.

The tunnel contract will interface additionally with:

Access roads: All access roads to be usable when the tunnel contracts become effective
Social Uplift Program (SUP). There is a simultaneously implemented Social Uplift Program which is part of the Melamchi Water Supply Project.

II. Specific Task for Tunnel Construction

The Consultant shall provide at the approval of the client a suitably qualified and experienced senior engineer familiar with the scope of the Works to assist the MWSDB in the procurement of the Tunnel Construction Contract and evaluation of the tenders. The Consultant shall attend such meetings and review the available documentation necessary to allow them to provide advice to the client on the selection of the tunnel construction contractor. Where practical staff involved in the evaluation of the tenders shall also be assigned to the Consultant’s ongoing services for continuity. The design of the tunnel contract works, including the headworks, has been developed sufficiently for tendering. The Consultant shall review the tender drawings and the Final Design Study Reports previously prepared and satisfy themselves the extent to which the Works are defined. Following this review the Consultant shall prepare a “Tender Design Review Report”. Following review and approval by the client the Consultant shall undertake detailed design, interpret and expand on or modify existing designs/drawings as required and check and approve working drawings and shop drawings prepared by the Contractor or suppliers.

I. Work Program: Critically review the contractor’s work program in relation to the targeted completion date and to ensure that it realistically reflects the available resources. Take measures as the Engineer to maintain the programme in accordance with the clients’ project programme and requirements.

II. Discrepancies and Omissions: In consultation with Client and the Contractor as required, resolve discrepancies and omissions in the contract documents.

III. Inspection of Goods: Inspect goods upon arrival and control test certificates provided by the contractors/suppliers, supervise and/or carry out tests as required.

IV. Ongoing Construction Inspection: Carry out the daily inspection of construction work with respect to adherence to the contract conditions including environmental measures. The inspection will include quality control (using appropriate report formats, and field and laboratory test forms), work measurements, record keeping and daily progress.

V. Environment protection clauses are included in the Construction Contract Documents. The Consultant will monitor the Contractor’s implementation of such environment protection clauses, will issue field instructions as necessary, and will monitor the implementation of such field instructions.

VI. Tunnel Headings – Ground Conditions: Provide for observation and monitoring of on-going tunnel conditions during construction at all headings with respect to integrity of the rock for the purpose of determining timely and efficient application of the temporary and permanent system for the advance on each tunnel face. The Consultant’s Geotechnical Engineer will lead the rock face mapping task jointly with the contractors Geotechnical Staff. The contractor will perform the mapping and propose lining details accordingly. The Contractor shall be responsible for the design, nomination on site and installation of initial support to excavations to ensure the safety and temporary stability for the duration of the Contract. The Contractor shall inspect excavation surfaces jointly with the Engineer as soon as practicable after each blasting round.

VII. Tunnel Support Design: The tender drawings for the tunnel contract provide indicative details of design for different classes of ground conditions and different support systems. The Contractor shall propose and the Engineer shall review and approve as appropriate the selection of the initial (temporary) ground support to be applied to the excavated tunnels. In situations where the Engineer and Contractor do not agree on the selected lining detail, the Engineer’s opinion shall prevail, and the Contractor shall proceed to install the lining accordingly. The Consultant shall be responsible for the design and nomination on Site of the permanent support to excavations which the Contractor shall supply and install.

VIII. Site Meetings: The Consultant shall lead regular site meetings and prepare the minutes from such meetings (based on a standardized format), proactively manage the execution of agreed actions.

IX. Measured Work: Works requiring measurements shall be measured by the Contractor with supervision of the Consultant. Work completed shall be clearly indicated on “As Built Drawing” maintained by the Consultant and up dated monthly as a record of work done.

X. Variations and Claims: Issue variation orders as required. The Consultant shall obtain prior approval of the Client before taking any actions under relevant Clauses of the Civil Works Conditions of Contract. The Consultant’s authority and delegated responsibilities will be advised in writing to the Consultant and copied to the Contractor before the commencement of the Tunnel Contract. The Consultant shall examine and assess the claims and time extension requests of the contractors and recommend his findings to the Client. In the event of any arbitration or litigation procedures, provide assistance to the Board of Arbitration or Court of Law, if so requested by the Client.

XI. Payments to Contractor: Check payment claims, guarantees, performance bonds, and all other required documentation against the contract, including the monthly progress payment claims submitted by each contractor. Certify payment of such amount of the claim as is adequately documented and supported in accordance with the contract.

XII. Coordination with Other Contracts: Support the coordination of the interface between the tunnel contract and others and together with the Engineer of any other contracts (water treatment plant, access roads EMP and SUP activities), support necessary co-ordination between these contracts.

XIII. Communication with the Client, Monthly Meetings: Besides regular contacts, the Consultant shall inform and consult with the designated representative of the Client without delay in case of major events threatening in the successful and timely completion of the works. The Consultant shall participate in monthly progress/coordination meetings with the PMU to be held in Kathmandu and make a short presentation on progress, problems, remedial action proposed, interface issues, and any other matters that should be considered by the meeting. The Consultant will also provide timely component information for project use in the MIS format established by the PMU. Submittals and reports will be generally forwarded to project headquarters both hard copy and electronic media.

XIV. Taking-Over: To carry out inspection and report to the Client prior to formal taking – over all or part of the works and issue defects corrections notice as required. Participate in final joint inspection and issue Taking–Over Certificate.

XV. Defects Notification Period: During Defects Notification Period, one year for civil works, to provide intermittent inputs to inspection and report on condition and defects.

III Specific Tasks – Cost Control

Account of Expenditures: The Consultant shall provide monthly detailed records and summaries of costs certified to date for the tunnel contract in tabular and graphical format..
Tunnel Support and Lining System: Tunnel support and lining system shall be proposed by the Contractor and approved by the Consultant. To reflect some expected variation in geotechnical conditions the costs shall be changed accordingly.
Final Measurements of Works: The final works are subject to final measurement under the terms of contract.
Variations: The Consultant shall issue variation orders as required, but is required to obtain prior approval of the Client for any variation before taking any action under relevant Clauses of the tunnel contract.
Claims: The Consultant shall number and classify each claim and time extension requests of the Contractors and recommend his findings to the Client. In the event of any arbitration or litigation procedures, the Consultant shall provide assistance to the Board of Arbitration or Court of Law, if so requested by the Client.

IV Training

The key training program delivered under this contract by the Consultant is to be specifically focused on tunnel construction supervising issues. It is envisaged that the training program will be carried out early in the contract period primarily for the benefit of the MWSDB staff.

Training should be implemented focusing on the following parameters:

Training course shall be organised in two two-week sessions; 1st session shall cover Modules 1-4, and 2nd sessions Modules 5-9
1st session should preferably be arranged already before the starting of the project implementation because it is important that the Client’s staff is aware of the contractual procedures in early stages of the project.
2nd session should start two-to-three months from the starting of the project implementation
Training Program shall be held in agreed location in Kathmandu or Melamchi Pul Bazaar.
The desired number of participants is less than fifteen persons
Training Program in Kathmandu will be conducted by the Consultant’s expatriate and local professionals

V Other Training

On-the-job training will be arranged for the Client’s counterpart staff throughout the project implementation. So called “Saturday sessions” will be organized in special topics when the need comes. Consultant’s experts will give lectures in special topics related to tunneling works to the Client’s staff.
Other training activities will be developed during the course of the project depending on the type of training considered essential and beneficial for the implementation of the Melamchi Diversion Tunnel.

The DSC consultant is the Consortium of POYRY Infra AG, POYRY Environment Oy, POYRY Infra Oy and HIFAB International in association with Multi Disciplinary Consultants (P). Ltd, Nepal.

For further information please contact:

Eptisa Servicios de Ingenieira S.L.
Emilio Munoz, 35-67. 28037 Madrid.
Tel/Fax – +34 915 949500 / +34 915 473934


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