EINRIP. Specification and Construction Issues

Transcription

1 EINRIP Specification and Construction Issues

2 There are a significant number of changes in the Specification Not all issues can be discussed here A more detailed list of changes will be provided with bid documents

3 The specification is based on the SRIP Specification with amendments Changes have been discussed and approved* in three workshops and by BINTEK Standards Sub Directorate *Except for rigid pavement which still requires final concurrence

4 The presentation aims to give bidders a taste of what to look for when estimating unit prices for EINRIP projects. The underlying message should be clear: Bidders should carefully review the Specification, Drawings and Bidding documents and must ensure that tendered d Unit Prices account for Specification and policy changes

5 This is not a Pre Bid Meeting Individual projects will not be discussed Discussion issues that apply to all projects should be self evident The drawings and BOQs define specific project issues

6 DESIGN REVIEW

7 Designs are fully detailed. d Therefore FIELD ENGINEERING and Design Review requirements will differ from the past.

8 Clause The Field Engineering review period is limited to 30 days after mobilisation. Only minor design revisions are permitted.

9 Clause Field Survey for Minor Revision: i the Contractor shall locate and propose corrections for errors and omissions the Engineer shall make corrections and interpretations deemed necessary

10 SUPERVISION

11 General Conditions of Contract: FIDIC Harmonized Version Engineer: RSC Team Leader

12 QUALITY

13 A SIMPLE RULE FOR EINRIP PROJECTS: SPECIFIED QUALITY STANDARDS MUST BE ACHIEVED

14 THERE WILL BE INDEPENDENT AUDITS SPONSORED BY THE LENDING AGENCY

15 Contractual and specified sanctions will be enforced if specified quality is not delivered

16 BIDDERS MUST HAVE A QUALITY ASSURANCE PLAN AND MUST BE SERIOUS ABOUT DELIVERING SPECIFIED QUALITY

17 There will be ZERO TOLERANCE for false laboratory test t records. False records can be identified by recognizable data patterns Quality Managers must not tolerate such practices

18 SURVEY AND TOLERANCES

19 The drawings provide complete alignment and level data

20 Construction tolerances are realistic and in some cases less stringent than in past Specifications they must be adhered to

21 Example: grade finished level (or sub grade) Reference Relative to absolute level SRIP Clause (3) (a) (sub grade) +1 cm -1 cm EINRIP based on Survey Standards, Setting Out and Earthworks Measurements Less stringent but (Report of a joint IHE and ICE (UK) Working Party, achievable and will be 1982) Table 4.1 enforced needs SETTING OUT pegs +2 cm -3 cm

22 A qualified surveyor preferably equipped with a Total Station must be provided to set out the works Specified construction tolerances must be achieved to satisfy layer thickness, riding quality, appearance and other objectives

23 BRIDGE TYPES

24 The following bridge structure types are used: Integral abutment Pre-stressed Beam Steel truss Multi cell box culvert NEW TYPE

25 AGGREGATE G AND SAND

26 A 3 stage crushing plant is required to achieve the specified aggregate shape for more heavily trafficked projects EBL 01, EBL 02, EKS 01

27 NEW SCREEN SIZE FOR AC BASE (if used) Aggregate sizes for AC (only if AC BASE USED) ( (or 7) Abu batu New screen size For AC wearing Therefore preferable to have a 4 deck crusher plant screen deck if AC Base is produced

28 Sand Washing Sand Equiv 75 specified for heavy traffic asphalt Sand for concrete <3% pass 75 micron washed THEREFORE A SAND WASHING PLANT WILL BE NEEDED FOR EBL 01, EBL 02, EKS 01 etc

29 TRANSPORT OF MATERIALS

30 All trucks shall be legally ll loaded d overloading will not be permitted

31 Bids must allow for legal loading egclause 6349(a)

32 Extra for Haulage of Excavated Materials in excess of 5 km Pay Item: 3.1 (9) Problem : a) BOQ quantity not possible without contractors work plan -?? b) contractors responsibility to find most efficient work plan c) big problem for Engineer to decide NECESSARY long haulage for payment and keep balanced budget SOLUTION: Delete Pay Item 3.1 (9), (Item still exists for bridgeworks)

33 THE PAY ITEM FOR HAULAGE OVER 5 km IS NOT AVAILABLE FOR EINRIP EARTHWORKS DIVISION 3 (ONLY FOR STRUCTURES DIVISION 7) BIDDERS MUST ESTIMATE HAUL LENGTHS AND ALLOW FOR TRANSPORT COST IN OTHER UNIT PRICES

34 DRAINAGE

35 Full design includes invert levels Drains must be built to correct invert levels and gradients Specification requires drains to be installed before earthworks Therefore maximum use of pre cast elements is recommended d to minimise i i delay

36 EARTH WORKS

37 Some projects require heavy earthworks to improve alignments. A vibrating gpad foot roller may be required

38 Pantura and EKS 02 5 problems OVERLOADING SOFT SOIL WATER

39 soft soil EINRIPSection Saturated Silty Clay problem (EKS xx projects) : Usually high moisture content prevents compaction. Therefore AASHTO CBR test is inappropriate to determine sub grade value for tropical silty clay Actual CBR on site for saturated silty clay << 2% Field CBR for saturated silty clay must be based on DCP or soil properties, not on AASHTO CBR Requires capping layer of 0.5 to 1.0 meter to develop an equivalent CBR 2 bearing capacity

40 Typical flexible pavement structure for saturated soft soil sub grade eg EKS Asphalt varies Aggregate base A 20 cm Aggregate base B 20 cm Selected embankment 30 cm Typical wet season standing water ae level e Lower capping layer (granular) 100 cm CBR Insitu subgrade << 2% cm

41 EINRIP earthworks measurement ROCK AND COMMON EXCAVATION + design reconnaissance bore holes at deep cuts to assess rock Surplus to embankment demand etc or declared unsuitable Used in embankment (or other project applications) PAY ITEMS: Rock and Common Excavation PAY ITEMS: Rock and Common Excavation Common Embankment

42 Unsealed shoulder material (Class S) Class B problems as shoulder Erodes easily permeable safety problem for motor bikes Class S = approx SRIP unsealed road gravel Class C

43 ASPHALT

44 Refer recent BM/EINRIP Asphalt workshop Filler silo required AMP 60 tph required for AC Additional equipment Power broom 2 sprayers with spray bar Waterpass for crossfall Other see spec 14 and 30 mm hot screens

45 PAVEMENT STRUCTURES

46 Asphalt Overlay Rigid Reconstruction ti Heavy patching Recycling Full construction Grade raise

47 Pavement design principles Real axle loads 15 year design for asphalt 40 year design for sub grade Test pit analysis if BB > 2.4 mm Minimum CBR 15 granular base support Reconstruct if AC thin and failed, BB > 2.4 and granular base quality is poor

48 Typical full construction (CIRCLY) Traffic ESA million (5 th power) <1 <2 <5 <50 >50 HRS 6.5 AC (f) rigid AC (c) 22.5 Cement treated base 20 unbound Base

49 Typical existing structure of local roads upgraded to National and requiring reconstruction Asphalt 8 15 cm cracked Sirtu cm

50 Reconstruction process: 1 remove asphalt (if milled it can be reused)

51 Reconstruction process: 2 Excavate widening to sub grade ( excavated material used as embankment if suitable )

52 Reconstruction process: 3 Trim to final sub base level or lower cast surplus to widening

53 Reconstruction process: 4 Make up to design sub base level with new material and compact existing and new in 20 cm layers

54 Reconstruction process: 5 Place and compact new pavement layers Asphalt varies Aggregate base A 20 cm

55 Reconstruction process: 6 Use milled asphalt as specified Asphalt varies Aggregate base A 20 cm

56 ROAD SIDE FURNITURE ETC

57 New guard rail end types Semi mountable curb for safety and aesthetic reasons Grated pit entries for drainage Invalid ramp for curb lines at intersections, pedestrian crossings and bus stops other

58 Vehicle accesses Will be provided d to ROW line Usually not shown on plan Standard or special drawings will be provided Mountable curb used when private access spacing less than 10 metres

59 CONCLUSION Quality standards will be enforced There are a number of changes in the Specification Certain additional equipment items must tbe provided dparticularly l for heavily trafficked roads Take account of these factors when pricing bids