module title temporary works civil engineering …：模塊標(biāo)題的臨時(shí)工程土木工程…

1、1 Temporary Works2Temporary WorksDefinition (according to BSI)Any temporary construction necessary to assist the execution of the permanent works and which will be removed (sometimes not) from the site on completion. 3Temporary Works(according to the General Conditions of Contract for Civil Engineer

2、ing Works, Hong Kong Government 1993 Edition)All temporary work of every kind required for the construction, completion and maintenance of the Works.4Common Temporary Works in construction sitesHoading & Fencing, Site offices, storage facilitiesExcavation supportsAccess ScaffoldsWorking Platforms5Co

3、mmon Temporary Works in construction sitesFalseworkShoringTemporary Access Bridges, RampTemporary Structures for Construction PlantsRiver Diversion Structures6Temporary Works and the Conditions of Contract General Conditions of Contract for Civil Engineering Works, Hong Kong Government 1993 EditionC

4、lause 10 Extent of Contract ( General Obligations )7Temporary Works and the Conditions of ContractThe Contractor shall, subject to the provisions of the Contract, execute the Works and provide all labor, materials, Construction Plant, Temporary Works, transport to and from the Site or in and about t

5、he Works and everything whether of a temporary or permanent nature required in and for such execution so far as necessary for providing the same is specified in or reasonably to be inferred from the Contract8Temporary Works & the Common Law It shall be the duty of any person who designs, manufacture

6、s, imports or supplies any article for use at work,(a) to ensure, so far as is reasonably practicable, that the article is so designed and constructed as to be safe and without risks to health when properly used;9Temporary Works & the Common Law(b) to carry out or arrange for the carrying out of suc

7、h testing and examination as may be necessary for the performance of the duty imposed upon him by the above paragraph;10Temporary Works & the Common Law(c) to take such steps as are necessary to secure that there will be available in connection with the use of the article at work necessary and adequ

8、ate information about the use for which it is designed and has been tested, and about any conditions necessary to ensure that when put to that use, it will be safe and without risks to health.11Temporary Works & Contract Pricing Requirements of temporary works: labor, plants, materials, construction

9、 methods(including safety provisions) and the associated cost need to be established at the tender stage.12Temporary Works & Contract PricingOtherwise the tender sum may not allow sufficient budget for the subsequent site activities in the construction phase, hence decreasing the Contractors profit

10、margin or to the worst incurring a significant loss at the end of the Contract13DESIGN OF TEMPORARY WORKSStandard SolutionsSolutions to temporary works problem by reference to tables/charts previously prepared for the likely variety of loadings that could be met in situations amenable to their use.

11、14DESIGN OF TEMPORARY WORKSRelevant information could be available from :I. in-house tabulations showing loads and spacing of materials used on a standardized basis;II. authoritative guidance documents resulting from research and testing e.g. CIRIA Reports, B.S. 15DESIGN OF TEMPORARY WORKSIII. docum

12、ents provided by manufacturers marketing proprietary equipment tested to comply with the relevant local legislation/industrial standards.16DESIGN OF TEMPORARY WORKSWhy Standard Solutions ? Requirements in relation to temporary works can be assessed with good accuracy.The pricing of various bill item

13、s will be more accurate. Standard solution tables provide site management with the means of checking the work of subcontractors involved in carrying out the temporary works on site.17DESIGN OF TEMPORARY WORKSDesigned SolutionsDesigned solutions become necessary for situations where the standard solu

14、tions are in appropriate. Competent persons should be employed in such particular site situations.18SCAFFOLDING Definition:a crucial item to ensure that workers have a safe place of work and a safe means of access to it.Related legislation:Strength and Stability; Platform widths for various purposes

15、; Provision of hand rails, toe boards, prevention of materials falling off scaffolds19SCAFFOLDINGCodes of Practice:BS 5973:1990 Code of Practice of scaffolding (design code)BS 1139:1981 Part 3 Specification for prefabricated access and worker towersNo codes of practice for proprietary systems20Termi

16、nology in Scaffolding LayoutStandardsLiftBayLedger/LacingDiagonal BraceLedger BracePlan BraceTransom21Terminology in Scaffolding LayoutPutlogCouplerGuardrailDecking/BoardingToeboardSole Plate/Board22Terminology in Scaffolding LayoutU-head/Fork headScrew (U-head/Base)JackProp (telescopic)Tie rod23Cou

17、plers & Fittings Standard 90 deg couplerFixed couplerSwivel couplerSafety/Check couplerPutlog headReveal pin24Types / Configurations of Scaffolds A. Tube and Fitting ScaffoldsPutlog Scaffolds :scaffolds are those which have one line of standards to support the outside of the scaffold deck, while the

18、 inside edge is supported from the wall being built. The putlog is a transom member with a flattened end to rest on masonry walling. The whole scaffold erection is slightly lean inwards to increase stability.Limitation - for use on load bearing walls only.25Types / Configurations of ScaffoldsIndepen

19、dent Tied Scaffolds :scaffolds are those have two rows of standards supporting the working deck. The transom members are tied between the two layers of standards and act independent of what is being built. For improving the overall scaffold stability, the structure is tied at some points to the new

20、building.26Types / Configurations of ScaffoldsSpecial Scaffolds for specialised workFree-standing scaffolds - movable and stable Vs overturning without any attachment to any other structure but occasional guy or raking strut support. (Covered by BS 1139 : Part 3. 1983)Slung Scaffold - those hanging

21、from a structure overhead but incapable of being moved sideways or raised or lowered. (Covered by 5973:1990)27Types / Configurations of ScaffoldsSuspended Scaffolds - working platforms suspended on wire ropes from a suitable structure above, such that they can be raised or lowered, but not moved sid

22、eways. (Covered by 5974:1982)28Types / Configurations of ScaffoldsB. Proprietary Scaffolding SystemsThe specialised systems are designed to avoid the use of loose fittings and are modular in concept. Their load carrying capacity and structural stability work on a deem-to-satisfy basis after extensiv

23、e testing to validate the performance figures by the respective manufacturers.29Comparison between Tube & Fittings Scaffold and Proprietary Scaffold Tube and Fitting ScaffoldAdvantagemore flexible to awkward situations and dimensions which do not fit the modules of proprietary methods.30Comparison b

24、etween Tube & Fittings Scaffold and Proprietary ScaffoldProprietary ScaffoldAdvantages:Connection methods provide a rigid connection to standards than conventional tube and fittingsThe members are of fixed modules and hence the scaffold set out itself. If dimensions are wrong, the pieces will not fi

25、t together.It is easier and quicker to train scaffolders.31Comparison between Tube & Fittings Scaffold and Proprietary ScaffoldProprietary ScaffoldAdvantages (Contd):Few loose fittings are needed.Quicker erection due to no coupling to be set out or done up required in the tube methods.Losses are min

26、imized because of the size of the standard components.32Comparison between Tube & Fittings Scaffold and Proprietary ScaffoldProprietary ScaffoldDisadvantage: the capital cost is grater than with tube and fittings.33Division between standard and designed solutionsBS 5973 recommends that the design of

27、 Tube & Fitting Scaffolds can adopt standard solutions (i.e. without design calculation) up to 50 metres high provided that they do not carry loads nor greater bay lengths than those specified in the document, nor subjected to loading of materials by mechanical means.The Proprietary Scaffold Systems

28、 all come into the standard solutions. Any modified approach need to be supported by designed solutions. 34Checklist for scaffolding requirementsPreparations for scaffolding specifications will be assisted by having available a checklist similar to one shown below of all possible types of scaffoldin

29、g that may be needed for both internal and external construction activities.1. External elevations2. Scaffold to roof level structures3. Hoist towers35Checklist for scaffolding requirements4. Rubbish chutes5. Loading towers6. Internal wall and partition scaffold7. Birdcage access scaffold8. Mobile a

30、ccess towers36Checklist for scaffolding requirements9. Truss-out Access scaffold10.Handrails and guardrails 11. Lift shafts12. Protective fans13. Other specialist requirements14. Protection requirements37Provisions in Scaffolding ContractsResponsibilities1. The scaffold owner shall declare the loads

31、 that are brought down by each standard. The hirer will be responsible for adequate foundations and this information on loading of standards is necessary for him to provide the necessary support.2. The hirer is responsible for the provision of sufficient anchorage points for a positive tie into the

32、structure, in accordance with BS 5973 or as may be agreed between the parties.38Provisions in Scaffolding Contracts3. Those erecting the scaffold will ensure that the scaffolding is soundly and adequately constructed and complies with appropriate Regulations (esp. in respect of safety) on handing ov

33、er.4. The legal requirements calling for regular inspections of the scaffold thereafter rest with site management.39Provisions in Scaffolding ContractsPricing1. Provision of scaffolding as described by the main or specialist contractor who is responsible for its provision;2. The extra over rate for

34、the hire of the scaffold if the contract period is overrun, as a rate per week;3. Hourly labor rates for alterations to the scaffold after the initial erection. 40Site Safety Regulationsfor Scaffolding WorksThe responsibilities of a contractor in working with scaffolds under the Construction Sites (

35、Safety) Regulations of Hong Kong are :41Site Safety Regulationsfor Scaffolding Works(I) ensure practicable, suitable and sufficient safe access to and egress from every place on site at which any person at any time works, and maintain it properly,(ii)ensure every place on the site shall be made and

36、kept safe for any person working there (iii)ensure that no scaffold is erected on the site or substantially added/altered/dismantled except under the immediate supervision of a competent person and by competent workmen of adequate and appropriate working experience.42Site Safety Regulationsfor Scaff

37、olding Works(iv)ensure every scaffold is of good construction, made of strong and sound materials and free from patent defect and properly maintained.(v)ensure every scaffold is kept so fixed, secured or placed in position.(vi)no part of structure or building is used in support for a scaffold unless

38、 it is strong and stable.43Site Safety Regulationsfor Scaffolding Works(vii) the scaffolds to be inspected by a competent person within the immediately preceding month,(viii) inspection reports to be made in approved forms by the person who is responsible for inspection which contain the prescribed

39、particulars and delivered to the contractor concerned.44Bamboo Scaffolds - AdvantagesFlexibilityBamboo could be cut and lapped through fastening thus tailor-assembled easily to suit the profile and contour for most construction structures even of very complicated geometry and shape.Bamboo scaffolds

40、could also be erected at any elevation of a multi-storey building, for instance truss-out scaffold structures, which is particularly advantageous in Hong Kong where tall buildings are crowded with limited space for access in general.45Bamboo Scaffolds - AdvantagesBamboo when combining with steel bra

41、ckets as the primary structural supports could be a very safe solution for most scaffolding work.46Bamboo Scaffolds - AdvantagesCost effectivenessAbundant supply of bamboo is available from the Southern China areas, thus reducing the cost of transportation for scaffolding work in Hong Kong.Fast grow

42、th in bamboo plantation could make it as a cheap and environmental friendly temporary works materialsThe cost is usually a few percent of that of steel scaffolding tubes.47Bamboo Scaffolds - AdvantagesSpeedinessBamboo is very light-weighted which can be handled by workers and it requires no machinery and sophisticated hand tools.This feature is leading bamboo scaffolds could be erected and dismantled much faster than other types of other types of scaffolding.48Bamboo Scaffolds - Common Causes of Fail