METHOD STATEMENT FOR MARINE WORKS.

This method statement describes in brief the broad sequence and method for excavation/removal of unsuitable beach materials, beach sand works, groynes construction and floating pontoon works to be carried out for the completion of the marine works.  The overall operations would be so programmed to comply with all contract specifications, achieve project milestones, and accommodate Engineers concerns and to ensure that personnel and equipment resources are optimally utilized, and construction is completed within the stipulated time in the allocated budget.

This method statement is preliminary and is meant for tender submission.  This will be finalized on award, incorporating Client’s comments, if any.  

SCOPE OF WORK.

The main contracting shall perform the site works for the completion of marine works.

The base scope of work shall include but not limited to the following:

(a)          excavation / removal of unsuitable beach materials

(b)          beach sand works

(c)          groynes construction

(d)          floating pontoon works

(e)          navigation buoys installation

(f)           submission of drawings and other relevant documents

GENERAL CONSTRUCTION ARRANGEMENT.

All activities, equipment, manpower, etc., to be used into the works, will be performed, checked, supplied, stored and handled in accordance with the prevailing codes, standard, specifications, design requirements, drawings, etc.

Parts of these specifications, instructions and rules are or will be included in the following documents.

a)           Project Quality Plan

b)           Method statements

c)            Project HSE Plan

d)           Guidelines from concerned Authorities, etc.,

Construction Preparation.

Construction preparation works shall mainly include setting-up of site facilities and other related facilities for equipment laydown yards, maintenance workshops etc., all as per our qualification.

MOBILIZATION.

Based on the agreed contract document and work schedule, the Subcontractor will mobilize all relevant personnel, plant and equipment to site. Personnel and equipment to be mobilized might come from various locations within the Middle East, consequently, the lead times required will vary.

CONSTRUCTION METHOD.

The following methods are based on our experience in executing similar types of operations and on the information available during the tender stage. It is presented here as an indicative procedure only.

On award of a Contract, the method to be used may be subject to adaptation or alteration to suit the prevailing work environment, conditions and operational circumstances. The following sections will describe the major construction activities.

Setting out & Survey Works.

After the detailed review of site layout plans and associated drawings, a thorough site/ marine survey shall be conducted to determine and to confirm the permanent reference points existing around the proposed work area. This activity will be done in coordination with the Client/ Engineer Representative. Necessary care will be taken to ensure all reference points are approved and correct.

During the handover of the site, reference points/ benchmarks will be established and permanently located. These points shall be marked on drawings and reflected in shop/construction drawings as well as in as-built drawings. The Geotechnical, Bathymetric, Topographical, Marine Surveys and Investigation, etc. (if required) will be carried out by a specialist agency to ascertain soil conditions as per the contract documents requirements.

Beach Development.

Silt Curtain Installation Works.

Connection of Silt Curtain.

For ease of transport and handling, silt curtains are packed and wrapped in individual bundles of 20m sections. The connection will be performed at site to be located as close as possible to shore in a location which allows for the curtain to be towed offshore using an appropriate boat. Once curtains are assembled and connected, furl curtains by folding curtain skirt and securing with rope every 1-2m.

Deployment.

Curtain furling straps should all be securely tightened between every float section and on end points to reduce towing friction. Always tow with both the Anchor Point and the chain ballast pocket.

According to layout for deploy by towing seaward end of curtain into position. Curtain furling straps should remain in place until anchored in the required position.

Anchors should be placed from the end section working backwards towards land. It is important that anchors are placed inside of the curtain to allow for tide and water movement (if any).

To place anchors, attach the anchor rope after the buoy to the designated anchor point on the curtain. Attach the anchor retrieval line at the yellow buoy to a suitable bow cleat on the boat. Reverse slowly letting the anchor line play out until the anchor itself is suspended midway between the curtain and the boat. Once the curtain is in position quickly release the rope at the cleat and allow it to fall.

Once curtain is securely anchored, it may then be unfurled by cutting the furling straps for each section.

Re-adjust anchoring if required.

Beach Excavation Works.

After completing the surveying works, the beach area shall be excavated to the required profiles.

Excavation will be done using a long boom excavator. An experienced labor will accompany the operations to observe the excavation development.

The excavations will be performed to the dimensions and elevations indicated on the approved shop drawing.

The Surveyor and Site Engineer will monitor the excavation slopes and depths to prevent over excavation of the area and will ensure that the excavation levels are in accordance with contract drawings and within the tolerance limits as specified.

Unsuitable excavated materials will be removed from site to designated dumping area offsite.

The area of excavation will be provided with adequate barriers, signboards, advance warning signs, etc. as required.

Beach Bund Construction.

Upon obtaining the required level of excavation and prior to commencing with the beach sand filling and profiling, a beach bund shall be constructed within the beach limit to prevent the sand from getting displaced/washed away by sea waves.

Beach Sand / Profiling Works.

The approved beach sand material will be brought to the site for stockpiling at a designated area.

After achieving the desired shape and slope, the tipper truck shall start dumping the imported beach sand within demarcated area, after which a land-based and/or long boom excavator on barge will start laying the material and evenly spread it over the area starting from the shallow water depth. The second load to be dumped over the formed layer and so on until the filling of the beach sand is completed as required.

 The same equipment will be used to profile the beach surface to the required slope and final level.

Removal of Existing Revetment & Defense Wall.

Prior to the commencement of dismantling work, the required formalities, approvals including as-built drawings, method statement, etc., shall be obtained from the Company.

After the survey work, the required equipment shall be mobilized to the site / location.

As a first step, the armor layer will be removed using excavator bucket by land and/or marine mode.

After the armor layer, the underlayer rock material will be removed using the same method and equipment, and finally the core materials.

All the demolished materials will be stockpiled in a designated area and will be later disposed offsite.

After complete removal of existing revetment, beach construction commenced.

Groyne Construction.

Excavation for Foundation.

The location of groynes shall be set out and marked by floating buoys. This activity will be carried out by the surveyor and divers.

Excavation will be made onshore by filling required areas to construct the bund (temporary work platform).

If a hard stratum (rock strata) is encountered during excavation, a rock breaker will be utilized to excavate to the required levels.

Excavated / filled surfaces shall be trimmed to the required slopes.

Geotextile fabric shall be laid and fixed in position as per the drawings and in accordance with the manufacturer’s instructions.

 

Placing of Graded Rock Layer.

Dump trucks / shovel shall deliver and stockpile the rocks on the placing area.

Material to be used shall be tested and verified in advance by independent laboratories.

Material shall be made available on site prior to installation.

Upon completion of geotextile laying, graded rocks will be placed uniformly to the required layer thickness.

Surface shall be trimmed and prepared to required slope for receiving the armor rock layer.

 

Placing of Armor Rock Layer.

Armor rock layer will be placed on top of the graded rock layer to the required thickness. A backhoe and/or crawler crane with clamshell shall be used in this activity. Armor rock shall be placed one rock at a time with the aid of divers.

The placement of graded rock shall proceed from the head of the groyne (offshore) to the tail (onshore).

 

Pontoon Construction.

The below described activities will be carried out during the construction of boats berthing pontoons.

 

Pontoon Design.

Pontoon detailed design shall be done by a specialized subcontractor.

 

Tubular Piles & Pile Guides Installation.

Tubular steel piles will be installed to restrain the complete pontoon system. An array of restraint piles will be installed to ensure integrity of the Pontoon system and piles. The steel pile external surface, including embedded length will be applied with protective coating as per the approved specification.

The steel tubular piles will be sealed with top plate such that condensation and moisture will run off the surface as specified in tender. The piles will be topped with conical shaped cap made with GRP.

The pile guides will be designed and installed to transfer the forces arising from the wind, wave and of vessel berthing, from the floating structure to the piles. These pile guides will be made with aluminum. These will be fitted with low-friction rollers or pads and designed to facilitate easy removal of the pontoon units.

Fabrication of Pontoons.

All the pontoons will be produced as per the Company requirements.  Before starting with the production of pontoons, the design and production methodology will be submitted for Company approval.  This will include mould structure, polystyrene placement, mould preparation, reinforcement arrangements, compaction method, de-moulding and curing, handling, storing, and transporting to site.

 

Pontoon Connections.

All fasteners and fixings for the pontoon system, fittings and furniture will be as specified. 

Installation of Floating Pontoon.

Once the piling works are completed, the Pontoons are lifted and placed between the piles such that the pile guides on the pontoons will easily move through the piles.

Before any lifting operation can take place, the supervisor should ensure that all lifting tackles, chains and the crane itself are in a good working condition, consequently, the weights of the structure being lifted should be known so as not to exceed the safe capacity of the lifting crane.

All the lifting belts, wire rope slings and D-shackles, etc., shall be certified and checked prior to the lifting operations.

The concrete pontoons shall be lifted using crawler crane, after hooking the slings/ attaching hooks in the given points considered in the pontoons for lifting. The pontoons are slowly and carefully lifted and placed between the tubular piles.

Pontoon Bollards/ Cleats Installation.

The mooring bollard will be fixed to the pontoon to accommodate mooring lines forces. These will be fixed to the edge of the pontoons as per the specification.

 

Access Gangways Installation.

Prefabricated aluminum gangways will be installed to bridge the gap between abutment work and the pontoon. These gangways will be fabricated as per the project specification. The gangways will be supported on the landward end by hinged bearings and at other end by rollers. The gangway landing area will be protected from wear from the gangway movements by an aluminum running plate.

Installation of Utilities & Accessories.

The exact location for the utilities and accessories such as electricity and water supply bollards, light pedestals, safety pedestals, stepladders and boat mooring bollards will be measured and installed in accordance with the approved shop drawings. All electrical cables and water hose pipes shall be fixed according to relevant authority standards.

Fender / Rubbing Strips Installation.

Fenders/ rubbing strips will be fixed to the sides of the pontoon to minimize vessel impact, chafing and abrasion of berthed craft and pontoon edges. Prior to installing it, Client’s material approval shall be obtained.