Title: Documentation for Design Changes - Metropolitan Atlanta Rapid Transit Authority (MARTA)
Date: October 9, 1995
The Doraville Station Parking Deck is a three (3) level concrete structure located adjacent to the Doraville Station, a new modern park and ride facility on the Metropolitan Atlanta Rapid Transit Authority (MARTA) system. The design of the Doraville Station was the responsibility of the a Prime Design Consultant (Prime Designer). The design of the Doraville Parking Deck facility was sub-contracted to a sub-consultant (Sub-consultant). The Prime Designer was hired through MARTA's consultant selection process and the Sub-consultant was one of the designated sub-consultants. The low bidder (General Contractor) on the Doraville Station contract entered into a contract to construct the entire project as the prime contractor. They, in turn, subcontracted the parking deck to a precast fabricator (Fabricator).
Following Notice-to-Proceed, the Fabricator reportedly called for changes to the design on the basis that the original design was flawed. The Fabricator volunteered to correct those problems at no cost to MARTA. At that time, the Prime Designer was no longer in business. When these complications developed, MARTA determined that they would review the changes made by the Fabricator in order to proceed with construction. These particular changes, however, were not well documented and not specific in terms of variance from the original design or design intent. The scope and definition of the "no cost" change to the contract was not documented. As a result, review of variation from the original design became very difficult.
Numerous problems with the structure were noticed after the construction had been substantially completed. This included rotation of the spandrel beams and cracking of corbels at the column locations. Temporary support of precast T-beams to support the parking deck structures became necessary because of insufficient bearing surface. A remedial repair program evolved with numerous levels of investigation. Repairs have been completed as of July 1995, and the final documentation of all repaired elements is occurring.
2. The Lesson
While construction of major facilities such as a parking deck of this size can be complex, MARTA has constructed numerous complex structures and facilities successfully in the past. The problem that occurred with this particular facility is that staff and management did not follow procedures that existed to control the design intent and to acceptably administer design changes as they occurred during construction. The following general observations are an outgrowth of not following the procedures in place at that time among the contractor, MARTA, and the designer of record related to design changes that were made by the construction contractor throughout the construction period.
• Observation: MARTA did not follow its procedures associated with change order and has since revised procedures to better document and control design changes.o Lesson: Not following prescribed procedures can lead to problems in managing capital projects.
• Observation: MARTA did not exercise controller the design changes made by the parking deck subcontractor.
o Lesson: Design changes, even at no cost, should be documented and assessed to determine their impact on the contractor.
• Observation: Review of shop drawings by other than the design professional, in this case by MARTA, caused dilution of responsibility.
o Lesson: The further removed the review of shop drawings, or any other design issue, from the design professional, the greater the opportunity for misinterpretation of the design intent.
• Observation: Fabricator stated design was flawed but did not define deficiencies. Contractor reportedly received MARTA concurrence to implement changes to the design without written scope definition at no cost to the contract.
o Lesson: Prior to proceeding with a construction contract change, proper documentation of design revisions needs to occur.
• Observation: Lack of documentation of the Fabricator's changes left numerous issues that needed to be resolved during subsequent repairs.
o Lesson: Lack of documentation leads to extra effort and protracts the completion of any revisions to the contract and ultimately the contract deliverables.
• Observation: Contract closeout procedures are focused on the Construction Contract. Less attention was paid to closeout of the design contract and As-built documentation.
o Lesson: Proper closeout of a project should include documentation by the design professional of the as-built product including all changes.
The general lesson is that in the preparation of procedures, they should be developed so that no individual can circumvent the process and that only through multiple failures at various levels of authority can major problems arise.
Analysis and resolution of the above issues has resulted in MARTA making significant changes in procedures, management personnel and reporting, since the construction of this facility. MARTA believes that they now have a process in place which will not allow similar problems to occur in the future. MARTA also has revised certain procedures associated with the standards for design and construction of precast parking deck facilities. MARTA has been a successful Grantee since the start of their rail program, but their experience in constructing precast concrete parking decks prior to the Doraville Parking Garage was limited and this may have contributed to the problems that occurred.
3. The Applicability
The lesson has general applicability to administration of changes to the design during construction.
A more specific application relates to many transit system stations that have precast concrete parking deck facilities adjacent to the station facilities themselves. The Doraville Station Parking Deck problems have pointed to a desire to exceed minimum design standards for precast concrete design, fabrication and erection (such as Precast Concrete Institute standards) to assure that the design intent is met and the standard of quality that is desirable throughout many of our transit systems is achieved.
4. Reference Documents
Structural Inspection and Analysis Doraville Parking Deck N920
Wiss, Janney and Elstner, June 17, 1993.