Severe construction problems, including cracks in the beams that hold up four elevated walkways, have thrown the District's $40 million municipal center a year off schedule and touched off a dispute between contractors and the Barry administration over hundreds of thousands of dollars in added costs.

The project at 14th and U streets NW, described by Mayor Marion Barry as one of his administration's boldest efforts in public works, has been bogged down in confusion and delays partly attributable to contractors who did not perform as expected, midcourse design revisions and land acquisition problems. The biggest factor, several contractors said, was the failure of the District's project managers to stay on top of the job, though city officials and the city's construction management firm disagree.

Interviews with contractors and examination of project documents show that the District and contractors have had to devote substantial effort to fixing problems, including window frames that did not fit, doors that did not close and pipes that initially were not protected from freezing.

Since before construction began in early 1983, Barry has cast the Frank D. Reeves Center of Municipal Affairs as a symbol of the city's commitment to minority contractors and to rebuilding distressed areas. The mayor plunked the building in the middle of a neighborhood ravaged by riots and crime like a palm tree in a desert, promising that it would spread green spaces and safe streets.

The original schedule called for some District employes to move into the building in December 1984 and the basic structure of the building to be finished by last March. Employes actually began to occupy some floors last November, and while the basic structure is almost done, work is expected to continue well into the summer.

While conceding that the project is delayed, officials of the D.C. Department of Public Works, who are in charge of it, said in recent interviews that they are satisfied with its overall management and cost.

They cited two major delays: from a window contractor who they said tried to change the design of the windows, delivered the wrong frames and finished work 12 months behind schedule, and from a church official who forced excavation crews to work around his storefront church for more than four months before he would sell his property. The window contractor said his company did not cause any unusual delays.

Ray Simmon, project executive for McLaughlin Construction Management Inc. (MCM), hired by the District to provide overall supervision on the job, also blamed Pepco for not installing power on schedule. Pepco engineer Bob Dickey disagreed, saying, "We were ready for them before they were ready for us."

Otherwise, Public Works Director John Touchstone said the project has had no more than "very typical construction problems" and that construction of the basic structure has come within budget.

"In fact," he said, "I suspect we've had less problems than most projects this size."

Touchstone declined to estimate how much contractors' claims -- for time lost as a result of delays or extended leases on office space elsewhere for city employes who were to move in last year -- will add to the cost of the project.

The department has awarded one contractor, L. Sanders Inc., an extra $36,000 for extended overhead costs on steel and metal work, and it has increased MCM's contract by $256,000. In addition, C.M. Tipnis, a vice president of Sherman R. Smoot Corp. of Washington, said his firm is filing for $600,000 to $700,000 in added costs, largely for time lost on concrete work. And MTI Construction Co. has submitted a claim for $165,000 for delays on demolition and excavation.

Horace Jones, the Public Works Department's acting director of construction and engineering, said the department plans to deny all claims and let the firms pursue their cases before the city's contract appeals board. Touchstone added that the city might recoup some costs by filing its own claims against contractors who it contends held up work.

As the project nears completion, the city is still trying to resolve a year-old, potentially serious problem involving the concrete beams that support part of the floor and one end of a pedestrian walkway on the third through sixth floors.

Almost as soon as workers finished erecting the walkways, the beams cracked at the corners, according to Tipnis. Several beams in the basement developed cracks of a similar nature, he said. Smoot poured the concrete on the job.

Smoot employes, fearing that the walkways could collapse, alerted project managers and VVKR Inc., a major architectural and engineering firm that designed the structure of the building, fashioned repairs.

At VVKR's direction, Smoot workers reinforced the beams supporting the four walkways in December 1984 by installing high-strength rods perpendicular to the cracks and bracketing them with steel plates. In the basement, workers widened concrete pillars under the beams to provide a better brace.

Since then, Smoot, VVKR, the construction management firm MCM and the city have gone back and forth on whether a safety problem exists.

Tipnis visited the building last summer and said he decided the cracks on the upper floors still "looked open and very vulnerable." He wrote to MCM in July that "we feel there is a serious problem at hand, and we fear . . . sudden failure" of the beams.

But Richard T. Ball, a VVKR structural engineer, wrote to MCM the following month that he was certain that the reinforced beams could support their loads. He recommended that the District remove temporary shorings that were put under the beams and measure the cracks to see if they had worsened. Reassured, Tipnis said at that point that "as far as we were concerned, the matter was closed."

Six months later, Jones weighed in with the department's concerns. "We are not satisfied with the corrective measures taken to reinforce the beam failures," Jones wrote in a letter to MCM, received Nov. 22.

"We will require the design and installation of additional support systems that will insure the structural integrity of this section of the building," the letter said. "You are therefore directed to engage the services of a structural engineering firm to design additional support systems for the failed beams."

In a recent interview, Touchstone said the letter overstates the city's concerns. "Ball is satisfied, MCM is satisfied, my engineers are not raising any questions," he said. He said that while the city has not formed a final opinion, it appears that "the problem is solved."

Simmon of MCM, present at the same interview, said the construction management company has not hired a structural engineering firm as Jones' letter directed, noting that VVKR is already under contract with the District. He said the area of the building in question is being tested, adding that he expects to deliver a report to District officials soon. In the meantime, the District has kept the temporary supports under the beams.

The extent and cause of the cracks are a matter of debate. Simmon, the MCM project executive, said Smoot workers failed to install a slide-bearing assembly on the sixth floor designed to allow the beam on that floor to move slightly at the joint.

He said that as a result, the sixth-floor beam cracked. He said there were no significant cracks in beams on other floors.

Smoot executive Tipnis, who is a structural engineer, acknowledged that Smoot workers did not install the assembly on the sixth floor, but he said that this omission did not cause the cracks. He said the beams fractured in the same place on the lower floors, which suggested a design flaw. Ball, VVKR's engineer, agreed that cracks developed in each beam that supports a walkway.

In his view, Tipnis said, "This was a design error . . . . It was a very tricky design. It put a very heavy load on a very short stub" of concrete.

Ball said while the cause of the cracks was not entirely clear, "I suppose if we [had] put more steel in [the beams] we probably wouldn't have had that problem. I would surmise that probably would have been the case."

He added that "the problems here are small compared to the whole building."

Thomas Carcaterra, a structural engineer with 30 years' experience hired by The Washington Post to examine the problem and give his opinion, said the initial drawings for the project appeared to show insufficient vertical and diagonal steel reinforcements in the beams.

The long lag in the resolution of the walkways issue has been mirrored throughout the project. Several contractors fell far behind schedule and had to be continually hounded by MCM, project documents indicate. In one case, MCM hired another firm to complete work a contractor did not finish.

AMPAT/Southern Corp., the window contractor, caused the biggest delay problems, District officials said, and still has not delivered the exterior glass doors. MCM officials wrote to the Glen Burnie, Md., firm in November saying that they consider the company responsible for "all damages" from delays.

James Brown, a vice president of AMPAT/Southern, said the firm "had no problems . . . other than normal construction problems. We've had a very good rapport with the District. It has worked well." Brown declined to comment further.

Missing windows and skylights held up interior work on the building, according to District officials, and they contributed to what contractors described as serious water problems during the last year.

In addition to data about the window openings and skylights, project files show that water leaked in from the roof. According to minutes of MCM meetings, water infiltrated sensitive areas such as the electrical switch gear rooms and elevator shafts, ruined drywall and insulation and delayed certain types of work while repairs were made.

Simmon, of MCM, said every construction project undergoes similar water problems until the building can be closed in.

Besides AMPAT/Southern, MCM criticized a number of firms for impeding progress, project files show, including three firms that MCM said were not providing enough manpower.

The city itself added to the delays through the time it took to select contractors, project records show, and a number of contractors who worked on the building said MCM compounded the problem by being slow to respond to their problems with design or coordination.

"You needed to have much closer control over the job," said one major contractor, who asked not to be identified. "They didn't have that. Almost everybody who worked on that job ran into difficulties."

Simmon of MCM said, "The time for response was normal, or even early, when you took into consideration the type of question asked. Some things are not as easy to redesign as others."

The project needed particularly strong managers because public works officials planned it as a "fast track" operation in which engineers and architects would still be at work on the design after construction was under way.

And public works officials opted for a "construction management" style of construction that required exceptional coordination: Instead of hiring one general contractor who would bring on its own subcontractors, city officials hired more than a dozen contractors directly and employed MCM as their overall supervisor.

Minority contractors won 84 percent of the work, but in several instances the bidding process took so long that public works officials gave up and let MCM find its own subcontractor.

The agency twice solicited bids for brick and concrete paving work, for instance, but only one minority firm responded each time, with a price much higher than the government's estimate. By the time the District handed the contract over to MCM, six months had gone by.

More time slipped away, several contractors said, while they waited for MCM to respond on behalf of the District to their requests for clarifications on the design.

Bill Millios, project manager for Johnson Controls Inc., said he waited months for responses to his questions on installing automatic temperature controls. "Sometimes I just didn't do anything until I got an answer," Millios said. "Sometimes I just did what I thought was right."

Contractors were particularly anxious for answers from MCM because in some cases they were working off drawings that were not originally complete. One contractor called his assignments a collection of "afterthoughts."

Initial drawings, for example, left out heating for some areas where pipes could easily freeze, according to Wink Palmer, project manager for E.J. Murray Co. Inc., the mechanical contractor. "There were some areas that were missed that should have been picked up," he said.

VVKR submitted supplemental drawings for heating in the area of the pipes.

R. Randall Vosbeck, president of VVKR, said that gaps in design generally occur more frequently on fast-track jobs, but he said he saw no significant oversights on the drawings for the municipal center. "You talk to any contractor on any job and you'll find them complaining about the architect," he said.

Errors by some contractors helped to create a project that went partially in circles, contractors and trades workers said: Workers put up some walls only to take them down, installed some doors only to find they were out of plumb, put in sills for a number of elevators and windows only to discover that the bench marks by which they had been set were wrong.

In early spring of last year, top public works officials replaced Michael Hurd, the agency's project manager. "We felt things weren't moving as fast as we could," said Jones of the agency.

By September, public works officials had decided that they had to assume much greater control. MCM advised all contractors that public works officials would be on the job site every day, reviewing their work schedules and manpower, issuing directives, and expediting answers to contractors' questions.

To some contractors, the push from the public works department comes too late. "I just want to get my money and get out," said one contractor.