Site preparation, Environmental Protection and Landscaping Part 2

6. Notice of commencement

The Contractor shall give to the Engineer written notice of blasting operation. The works shall not be commenced until written approval has been received from the Engineer.

7. Environmental Protection and Landscaping
7.1. Discharge of water into existing streams

The Contractor shall make provision for the discharge or disposal from the Works and Temporary Works of all water and waste products however arising. The methods of disposal shall be to the satisfaction of the Engineer and of any authority or person having an interest in any land or watercourse over or in which water and waste products maybe so discharged. The requirements of this Clause shall not limit any of the Contractor’s obligations or liabilities.

7.2. Erosion and Sediment Control

The Contractor will undertake the following erosion and sedimentation control measures during the construction phase of the project.

Development of Drains and Dikes: catch and diversion drains shall be laid to ensure runoff from the construction works is directed into existing watercourses. All drains constructed will have a parabolic or trapezoidal cross-section. Interceptor dikes made of compacted material will be laid to convey water to stable outlets at non-erosive velocities. Dikes will have minimum ridge height of 0.5 m, minimum top width of 0.8 m and maximum side slopes 2:1 (horizontal to vertical).

Development of Bank: Sedimentation basins shall be constructed off-stream to remove sediment-laden runoff. The basins shall be located at points where the terrain provides maximum storage benefits. Desilting will be done when the capacity of the basin has been reduced by 30%. Effluent turbidity shall not exceed 200ppm.

Removal of vegetation and topsoil: Clearing shall be restricted to only those areas where the commencement of work is imminent. Clearing of areas not immediately required for the works shall be carried out at later time to suit the requirements of the construction program. Stockpile construction and maintenance – Smooth and free draining stockpile of removed topsoil shall be constructed with batter slopes not exceeding 1.5:1, and height limited to two meters. Compaction of the stockpile will be done by equipment necessary for the hauling, placing and spreading of the topsoil material. All topsoil stockpiles will be ripped to ensure the retention of moisture and the promotion of regrowth.

Resurfacing: a disturbed area that will be left exposed more than 30 days and not subject to any construction will receive temporary seeding. Following initial disturbance or rough grading, all critical areas subject to erosion (for example steep slopes) will receive temporary seeding in combination with straw or another suitable material.

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Site preparation, Environmental Protection and Landscaping Part 1

1. Clearance of Sites

The Contractor shall clear the reservation widths for pipelines and the sites of structures free of all vegetation, including trees up to 0.50 m girth measured 1.00 m above ground level, and all superfirical obstacles such as road surface, kerbs, bricks, rubbish and/or other objectionable matter.

Where required the Contractor shall also clear the sites of trees over 0.5 girth. Buildings and/or structures.
The extent of Contractor’s clearing and grubbing operations shall be the minimum practicably necessary for the construction of the Works.

2.Protections

Trees and/or other vegetations designated for preservation shall be kept free from clearing operation and be protected from injury during execution of the Works.

3.Road furniture

Unless otherwise directed by the Engineer the Contractor shall remove and re-install any road furniture (such as street lighting, traffic signs or traffic lights) that has to be removed during the progress of the Works. The cost of this work shall be deemed to be included in the Contractor’s bid.
Installation of the road furniture shall take place at its original location, in a condition at least equal to that prior to removal and as soon as practicable after the completion of pipe laying at a particular location.

4.Disposal
Remnants of vegetation, including trees, stumps and roots, shall be disposed off site by the Contractor.

5.Blasting
No blasting shall be carried out without the written approval of the Engineer.
When necessary, blasting for clearing boulders and/or rock masses will be permitted only on written approval of the Engineer and when proper precautions are taken for the protection of all persons, the Works and public and private properties.
Blasting shall be carried out in a controlled manner and to the required depth, amount and extent necessary and only with explosives of such quantity and strength and in such locations as will not structurally damage the material to be blasted outside the prescribed limits. Any damage to the Works or properties arising from the blasting shall be repaired by the Contractor to conform to the condition existing prior to damage.
Before any blasting is carried out, the Contractor shall ensure that adequate measures that are necessary for the safety and protection of persons and property against injury or damage had been provided and warning signs and signals had been installed, all to the satisfaction of the Engineer and other authorities concerned with safety and public order.
Explosives and detonating caps shall be stored, handled and used in accordance with Statutory Regulations and national guidelines. Only qualified and authorised personnel shall held and use explosives.

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Earthwork specification part 2

2. Excavations

2.1. Excavation Method Statement
The Contractor shall prepare a method statement of his proposal for earthworks operation for each particular part of the Works to be constructed at any one time, detailing the location, programme of excavation, temporary supports and the placing and handling of the spoil.
The Contractor shall submit of the Engineer’s approval his proposed method statement at least twenty eight days before his intended date to commence earthworks on each particular part of the Works.


2.2. Trial holes
The Contractor shall excavate any trial holes he may require to determine the position of underground services, sub-soil drains or for any other reason. The Contractor shall arrange for the refilling and reinstatement of trial holes to be carried out immediately the required information is obtained. The reinstatement of the surfaces of trial holes shall be carried out to the approval of the Engineer.

2.3. Extent of Excavations
Earthworks shall comply with BS 6031.
The extent of excavations shall be the minimum necessary or practicable in the opinion of the Engineer for the construction of the Works.
The construction of open trenches shall, at any one time, be limited to lengths previously approved by the Engineer. Work on each approved length shall be completed to the satisfaction of the Engineer before work on any new length is commenced.
Trench widths shall be as shown on the drawings.
No excavations with battered sides will be permitted in public highways, private gardens or within 3 meters of any building or other structure.


2.4. Stripping of topsoil
Topsoil shall be stripped from the whole or part of the Site to a depth of 250 millimeters and set aside for re-use as a separate operation prior to any further excavation, which may be required.
Topsoil shall include any surface material capable of supporting vegetation and suitable for use in soiling areas to be grassed or cultivated.
The Contractor shall not dispose of surplus topsoil without the permission of the Engineer.

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Earthwork specification part 1

1.General

1.1 Notice of Commencement
The Contractor shall give at least seven days written notice of his intention to commence earthworks on any part of the site ans shall furnish the Engineer with all ground levels and other particulars he may require for the purpose of carrying out measurements.
Earthworks shall not be commenced until written approval has been received by the Contractor from the Engineer.

1.2. Soil Investigation Reports
The Employer has carried out soil investigations in each town. Soil investigation reports are available for inspection during the Bidding period in the offices of the Employer. The Contractor shall take all such additional steps that he considers necessary to familiarise himself with the surface and subsurface conditions at the site.
Soil investigation data is furnished for information only and it shall be expressly understood the Employer will not be held responsible for any interpretations or conclutions drawn therefrom by the Contractor. If during construction the soil conditions prove to deviate from those set out in the soil investigation data so that an effect may or will be experienced on the work, the Contractor shall immediately inform the Engineer.

1.3. Earthworks to lines and levels
The whole of the earthworks for the Works shall be carried out to the required dimension and levels.
For the purpose of the Specification, the term "ground level" shall refer to the ground surface before the start of earthwork operation, but after the operations of site clearance. The expression “formation level” where used in the Specification shall mean the excavated foundation level of the structure concerned including the level at the top of blinding concrete.

1.4. Borrow area
It is the Contractor’s responsibility to locate the borrow areas for all kind of materials and obtaining, transporting and placing them when needed for the execution of the Works. The Contractor shall obtain the approval of the Engineer for the areas as well as for the materials he proposes to use.
Fill material for incorporation in the Works shall be obtained from approved borrow areas after the completion of any tests to confirm the suitability of the material.
On completion of excavation, the Contractor shall trim, grade and leave the borrow area in a tidy condition and shall carry out any further earthworks necessary to prevent accumulation of water in the area.

1.5. Disposal of surplus excavated material
The Contractor shall be responsible for negotiating and securing suitable areas for disposal of surplus excavated materials and shall pay any fees or other payments associated with such disposal.
In connection with the disposal of excess spoils, the Contractor shall be responsible for the following during the Contract period:
a)Upgrading the strength and the quality of the existing access road(s) and maintaining the same in good order and final reinstatement.
b)Keeping vehicles clean when leaving the tipping area(s) and to ensure they do not contaminate public roads.

1.6. Samples and testing
Materials proposed for use during construction shall be tested on site in accordance with the procedures as prescribed in BS 1377 to determine its characteristics and suitability. The Contractor shall perform the following material tests and obtain the Engineer’s approval prior to the use of materials:
a)Determination of field compaction of excavated or imported fill, and determination of optimum dry density.
b)Grading tests for granular and other fill.
The Contractor shall submit to the Engineer for approval samples of each types of filling to be used in the works.

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About book: Practice and Procedure for the Quantity Surveyor (10th ed.)

Author: Christopher J. Willis, Allan Ashworth and J. Andrew Willis
Publisher: Blackwell Scientific Publications

Contents summary:

Quantity surveying practice
1. Structure of the construction industry
2. The work of the quantity surveyor
3. Private and public practice
4. Contracting surveying
5. Organization and management
6. The quantity surveyor and the law
7. Information technology

Quantity surveying procedure
8. Cost control
9. Procurement
10. Preparation of contract documentation
11. Post-contract procedures

Specializations
12. Project management
13. Litigation and dispute resolution
14. Special client services
15. Research and Development

By hamo - Giaxaydung.vn

Boq - are they still useful and relevant today?

Historically, the formal form of Bills of Quantities (BQ) was introduced in the United Kingdom after the Industrial Revolution in the 19th Century. They were mainly used by master tradesmen for paying their workmen and
claiming payments from building owners by submitting it as partisan Final Account. BQ are widely used in most of the Commonwealth countries such as Australia, New Zealand, Malaysia, Hong Kong, South Africa, India, Pakistan, Nigeria, Kenya, the Middle Eastern countries etc. particularly in the traditional procurement system. BQ are mainly used for cost estimating and more importantly, as part of tender document for use in soliciting ompetitive tenders from contractors. They are also compiled together with contract form to form a contract document. However, as construction industry evolved and changed technologically, economically, legally and procedurally, so is the use of BQs in construction projects. It has been the subject of scrutiny and criticisms by the construction community. It was highlighted that the use of BQ in the UK construction industry is declining and it is possible that they will vanish from the industry in the near future. In 1991 the Royal Institution of Chartered Surveyors revealed that between 1984 and 1989 the usage of s in building works in the UK declined in value to almost 10%. Several reasons were given for such a situation. These include the lack of use by the project teams, its limited use after the tendering process and the increased use of more “advanced” non-traditional procurement system by the industry. That was the situation and prediction made twenty years ago. The question now “What is the situation in our construction industry today? Are BQ still relevant today, especially when more and more projects are contracted out using the non-traditional procurement systems? Are they still useful to the clients, architects, engineers and contractors throughout the construction process? This paper looks at the issue of BQ, their weakness and potential in the construction industry.

By ChutMayMan - Giaxaydung.vn

Reconmended bid procedures part 4

4. Day and time for receiving bids

The Issue: Upon what days of the week, times of the day and under what conditions should bids be received?

Discussion: Owners who wish to receive the most competitive bids must recognize that the construction industry has certain days and times to tender bids which are much preferred. The preferred days are Tuesday, Wednesday, and Thursday. The preferred time is a time specific between 2:00 p.m. and 4:00 p.m. local time. Bids tendered at times and on days other than these will receive substantially less coverage and very likely will be higher.

Recommendations:

1. Bids should be received at a specific time between 2:00 p.m. and 4:00 p.m. on Tuesday, Wednesday, or Thursday.

2. Bids should not be received on holidays, on the day before or after holidays, nor during the week between Christmas Day and New Years Day.

3. Prime Bidders should be afforded telephones in close proximity to the place for receiving bids for receiving and recording last minute changes to their bids.

4. The time of receipt should be clearly stated and strictly enforced. An official clock should be displayed in the place receiving bids, and the person receiving bids should stamp bids received with the time of receipt and publicly state when the time for receipt of bids has elapsed. Bids received after that time should not be accepted.

5. The Owner’s construction budget for the project and basis for selecting the low bidder should be announced prior to opening bids. See also Section 10, Pre-Bid Conference and Section 19, Owner’s Proof of Financial Ability.

6. Bids should be publicly opened and read aloud. Obvious problems with a bidders responsiveness (e.g., no bid bond, failure to acknowledge addenda, failure to comply with listing requirements, etc., should be noted). If protests are allowed, the mechanism for them should be set out in bidding documents.

7. Other pertinent bid information (alternates, Subcontractor listing, etc.) should also be read aloud.

8. Interested parties should be allowed to review the bidding documents of all bidders.

9. The schedule for award should be announced. Bids should not be held longer than sixty (60) days without an award announcement being made.

10. Complete bid results should be formally published in a timely way.

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