R K Dhiman, Superintending Engineer (Civil), BRO, HQ Deepak, Shimla.

Introduction

Success of any project depends upon how best the activities are managed from conception till completion. There are various steps which add to in overall completion of the project viz. timely decision, timely approval of design, & drawings and financial management. There is a saying that “stitch in time saves nine.” In case of bridges also final completion depends upon how best the critical issues/are managed/ decided during the process of construction. To get the project completed in time most important point is selection of right contractor for executing the work, pragmatic time schedule and efficient management of the contract. All the bottlenecks be attended to as a joint effort of the project. The management should be fully conversant with the growth of activities in a bridge project in advance. Various aspects for effective construction management of bridge activities have been discussed in this paper.

Management Requirement

With large amount of infrastructure development activities around us, specially for four laning and other highway work, sizable funds are dedicated for construction for road project, it would be prudent to have these projects completed well in time rather than having delayed completion. Accordingly project preparation and process of giving the work to the suitable contractor is judiciously decided.

The necessity of efficient management is actually felt due to:
  • Works are to be completed in time as per schedule of work as funds are fully dedicated.
  • Requirement of quality and advanced techniques of design to give slender structural members and impart optimization.
  • Increase in size of projects involving large quantities of construction materials to be handled and innovative designs for bridges are being finalized viz cable stayed bridges or other long span bridges.
  • Increase in complexity of project involving high grade materials.
  • Shortage of skilled manpower specially in case bridge projects are located in remote area.
Due to the above requirements, the construction equipment is required to be carefully identified and assessed so that full advantage can be taken of the productive potential during its use at site. This requirement can be finalized based on type of design of foundation or superstructure and ground strata and the proposed period of completion of the particular project. The costly equipment cannot be left idle and should be utilized meticulously to have optimum usage. Decision making during the process of execution plays a vital role in overall completion. This may be technical, administrative and other related matters. For repeated type of problems we must lay down the schedule for decision and should not delay beyond certain period. Timely decision pays its dividends but the delayed action has multidimensional effect on the particular job. Any committee or Board of Officers formed to take decision/ review certain technical details based on actual construction problems vis-à-vis problem anticipated before the start of work be reviewed to stick the time schedule. No extension to such Board/Committee be considered. This will provide smooth flow of activities at site and bridge can be completed in time.

Bridge Construction Overview

Planning and monitoring is basically what is to be done in due course of time, and how it is to be executed in the planned/allotted period for the particular bridge. All the pros and cons of the likely problems in the anticipated period need to be examined. Also the records of important points are made available at site with executives as follows:
  • Why the particular site was selected for the bridge.
  • Why particular type of bridge is proposed. (structural arrangement)
  • Site data
  • Proposal for preparation drawing.
  • Soil strata in the form of bore log.
  • Model study detail if already done for scour assessment.
  • Salient features of the bridge and quantities of each items involved.
  • Upto date approved structural drawings.
  • Details of all meetings and up to date decision if at all taken.
  • Decision making mechanism in case of any dispute i.e. Dispute Review Borad (DRB) be already finalized.

Bridge Foundation and Substructure

Foundation construction for any large bridge takes time. Problems encountered during construction of foundation depend upon type of foundation, soil strata encountered, equipment/plant deployed and logistic problems. Construction difficulties anticipated during the execution be kept in view while planning the works/ period for the job. Foundation can be opened foundation, pile foundation, well foundation or any other types of foundation. In case of well foundation, the various type of soil are encountered and it becomes difficult to give any clear time schedule about the sinking of wells unless the soil details are very clear and the anticipated profile matched with the actual encountered. In case of bouldery and clayey soil the rate of sinking schedule is likely to be slow when compared with the sandy soil. Also there may be requirement of pneumatic sinking technique subsequent to open grabbing due to difficulties in sinking of well. As the cost of pneumatic sinking is very high, this should be deployed judiciously. In such cases, there is need to keep the details of all the sinking difficulties in a systematic order and this can be reviewed in consultation with decision making authority. Review of soil parameter if required be given more attention and wherever required the details may be referred to material testing laboratory but within the time schedule. This may be helpful to recommend revision in foundation level, wherever possible based on soil data report. Tough strata in the foundation stage should be considered as engineering friendly

Superstructure

For particular site there are numerous structural arrangements possible. Final proposal be made based on the greater examination of site condition may be technical, aesthetic and construction methodology. Special care need to be taken in case of deep gorge where there is sizable difference between soffit level and bed level. This may pose difficulties for staging and shuttering. Proposal recommended for site should be well read in advance. After the proposal has been finalized for particular bridge, the construction can be planned. The quantities of each items involved and execution method be listed. Basically method statement should be kept ready for overall execution including job estimate. This data will be kept to ensure smooth progress of project.

Management of Construction Activities

Management of bridge construction demands that construction manager to reorient all the resources in such a way that the project is completed without any time/cost over run. Output of the work depend upon how best the activities are managed which will vary from site to site based on many factors. Based on the experience, various aspects be identified for efficient construction management. Schedule of construction based Critical Path Method (CPM) be prepared along with major milestone and Bar Charts. Latest software management tool can be used for this in case of a major bridge project. Design of Bridge is a post sanction in case of departmental construction and after tendering action in case of bridges throughout contract. It is necessary that design must be preceded by at least six to eight months or say 50% ahead of execution of concerned event. It has to be ensured that this should be completed well in time. Reviseddesign if any should be updated and clarified without delay. Observation on the approved design drawing if any be passed to design office immediately to make the changes. This is most important in case of foundation where design soil parameter needs to be adhered to. These may vary on actual execution and require review of design. To keep details with design office it is necessary that progress of foundation work be well informed to the design office.

Plant Management

Requirement of equipment/plant be assessed systematically and accordingly action may be taken to arrange this for a particular job.
  • Quantum of work covering all the items with specifications
  • Time available for work excution
  • Details of equipment and also minimum requirement as per job position.
  • Rated capacity of equipment/ plant
  • Assessed capacity
  • Schedule of maintenance
  • Inventory of spare parts required
  • Repair cover to equipment/plant
The layout should ensure minimum movement of material, equipment and personnel of the area is an essential condition, for operation of some equipment for example tower crane operation not possible at heavy winds speed. Stone crusher if required for site should be suitably located. Supporting facilities such as generator, office, stores should not be located in the path of dust, flow. The service road should be properly maintained. Receipt and despatch of equipment be kept in proper format to keep of details of its utilisation at site.

After staff has reported at site necessary action should be taken to utilise all the equipment. The required facilities for servicing and repair must be established to meet requirements.

Material Management

Material management is a parallel activity along with start of the Project. This cover procurement of camp material, office equipment, major purchased items, such as aggregates, sand, cement, steel, structural steel, shuttering consumables, electrical fittings. Forecasting of quantities and cost of various items on monthly basis must be done at least three to six months in advance which should be regularly reviewed.

Finance Management

No project or project management can be meaningful without this. In case of Government work the manager should get his budget fixed on monthly basis, on the basis of work done or minimum to be fed at site, on the decision of higher authorities. Key to measure financial planning lies in taking all above action and taking suitable measures at appropriate times to ensure that individual inputs are achieved to the maximum and capital investment kept at the lowest level.

Quality Management

Quality of work at site is most important activity and manager should always grapple to improve the same. Training to staff should be provided to update the quality control measure and it should become part of the work culture. At site laboratory be established to check the quality of concrete.

Tests be analysed at site based on the size of job. Mix design should be prepared based on the latest code and to produce the concrete of desirable strength. Compaction of concrete be given more attention before final setting. Latest guidelines issued by IRC and MORT&H be followed for systematic quality assurance. Quality assurance on ground improve the aesthetic of structures.

Safety Management

Safety of employees at site should be observed very seriously. All the workers be given briefing about the safety requirements based on the site hazards. Specially when the simply supported structure is attempted on deep gorge, suitable arrangement should be made to avoid any accident at site during insitu casting of superstructure. Also in case of foundation if the deep excavation is involved, the quality of surrounded soil be kept in view. There are incidents where few workers got buried in deep excavation due to sudden slide, this should be taken care. In case the well foundation is being attempted using double drum winch care need to be taken during grabbing process. During the diving process the proper coordination needs to be made between the diver and attendant to intimate about the problems if any, for which local signaling arrangements used, this can be finalised at site based on convenience. In case the pneumatic sinking is being used for well foundation, following safety measures, may be observed:
  • Accelerate circulation of air
  • Slow decompression
  • Duplicate and spare equipment
  • Illumination inside working chamber
  • Signaling arrangement
  • Caution about incidental loading
These precautions should be seriously followed to avoid any catastrophes at site. Safety management is also important in case on staging shuttering for superstructure. There are cases in the past where the collapse of shuttering/staging has led to loss of life. This needs check in before casting the superstructure. In case steel truss is being used as a staging arrangement, design and launching arrangement be thoroughly checked.

Documentation Management

Document management during the contract is an art in itself. Proper and systematic management of documents is utmost requirement for department as well as contractor. All the details should be property vetted by both the parties. Better documentation will avoid any disputes during the currency and after completion of contract (i.e arbitration cases areavoided). This needs special attention of the managers of both sides. Most of the cases being dealt by the arbitrator in our country, due to lack of understanding between two parties which, are further affected by improper documentation. In fact better documentation reflect the system of management in any project. Control estimate is required to be prepared annually to assess the job position. This should include work done till date and balance work in terms of money. This will be a guiding principle to progress the job in later period till completion. This practice is a must in all major bridge under construction. As project management has evolved, documentation has become a key skill particularly as projects become more complex and difficult. Organised documentation is the best defence against claims. Documentation that every project manager must have at their disposal are as under:
  • Proposal and Bid Estimates – These documents describe how the contractor envisioned the construction of the project and his plan to accomplish the work. It includes information about costs and schedule as well as construction methods.
  • Project Schedule - This is one of the most overlooked project records and it can provide the best documentation in a claim situation. The original baseline schedule sets the mark for monitoring the effects of any delays or unforeseen project disruptions.
  • Project Change orders – Any variances from the original contractual requirements must be documented and separated from the original scope of work requirements. Daily reports, time sheets, letters of correspondence and meeting minutes or any other documentation discussing agreements made between parties should be readily available.

Personnel Management

Manager should put the engineers, to activities they can perform better. Individual differences should be studied in detail to assign the suitable job to engineers, administration and account staff. Manager should be a good Psychologist to assign the work based on the inclination of the people at work. A considerable free hand be given to see what an individual can produce. He should be guided from time to time and work be kept on progress.

Decision making circulated, critical activities be cleared by manager after proper deliberations. Also care must be taken to select a new entrant suiting to the job for requirement.

Conclusion

With the changing scenario—there is urgent need to manage the bridge project effectively. Construction management basically is a tool to complete the project effectively within fixed amount but in less time. Manager should have knowledge sequence of all the activities. Decision making for both sides the contractor and the client needs to be fast and time bound otherwise the project will get delayed which will have cost over run. Control in form of reviewing monitoring has a catalyst effect to boost the progress.

Reference

  1. Dhiman RK - “Caisson Launching A- Case Study” Civil Engineering And Construction Review (CE&CR) - 1996.
  2. Dhiman RK - “Foundation Level for Bridges – A Programmatic Approach” 1996 New Building Material And Construction World (NBM & CW)
  3. Dhiman RK - Essence of Silt Factor for Scour Around Bridge Pier” – International Conference on Scour of foundation (ICSFI) held at Texas USA (17-20 Nov 2002)
  4. Dhiman RK - “Construction Problem of Bridges in Hilly Region – A Review”-1997 International Association of Bridges and Structural Engineers (IABSE)
  5. Dhiman RK –”Dimwe Bridge Foundation –A Case Study” 4th International Seminar on Bridge and Aqueduct – 1998
  6. Dhiman RK - “Well Foundation Construction in Bouldery Bed - A Case Study” International Association of Bridges and Structural Engineers (IABSE) Colloquium Feb 1999.
  7. Dhiman RK – “Affects of Flash Flood- A Case Study” – Disaster Management NERIST, Itanagar – 1999
  8. Dhiman RK - “Caisson Sickness During Pneumatic Sinking” International Symposium at University of Dundee Scotland (UK) - Sep 2003
  9. Dhiman RK – “Bridge Construction Problems and Solutions – A Review” 17th National Convention of Civil Engineering at Bhubneshwar – 2001
  10. Dhiman RK – “Extension of Span Ranga II Bridge – A Case Study” - ‘17th National Convention of Civil Engineering & Seminar on Modern Trend in Construction and Maintenance of Roads, Flyover and Bridges – Bhubaneshwar – Nov 2001’
  11. Dhiman RK - “Tilt Rectification of Well Foundation – A Case Study” - Indian Road Congress (IRC) Indian Highways May 2002.
  12. Dhiman R.K. – “Essence of Training of Manpower for Concrete Technology”, Sixth International Conference on Concrete Technology (6ICCT) at Aman (JORDAN) Oct 2003.
  13. Dhiman R.K. – “Construction Challenges for Bridges in Hilly Area – An Over View” - Indian Road Congress (IRC) Indian Highways Jan 2004.
  14. Dhiman R.K. – “Damages to Bridges due to Flash Flood – A Case Study” - Indian Road Congress (IRC) Indian Highways Oct 2004
  15. Dhiman R.K.- “Bouldery Bed Scour – Proposed Formula” Indian Road Congress (IRC) Journal 65 Vol-3 Paper No. 508. Nov 2004

NBMCW September 2007