The three-year widening of the Virginia portion of the Capital Beltway, already 11 months behind schedule, has fallen another five months behind because the ground is too frozen for workmen to lay asphalt.

At a Metro construction site in Arlington, a huge mound of dirt that will be used to refill a large hole sits undisturbed: workmen are waiting for the frozen dirt to thaw.

All over the Washington area, the bitter cold and occasional snow that has played havoc with area residents' heating bills and driveways has taken its toll on the construction business as well.

"It has completely shut down our operation," said William Hamp, construction manager for Excavation Construction Inc., which is widening portions of the Beltway.

Construction officials estimate more than 21,000 of the 30,000 construction workers have been laid off here since mid-December because of the cold.

Nationally, construction jobs have declined from 3,595,000 in January of last year to 3,541,000 for last month --a drop of 54,000 jobs, according to the Bureau of Labor Statistics. The total number of layoffs is expected to be higher when the full effect of the winter weather is measured.

"It's pretty bad," said John Quackenbush, secretary treasurer of the Washington Building and Construction Trades Council.

Hump said he has had to lay off 100 of his 125 workers since mid-December because it has been too cold to do any resurfacing. "The ground is frozen from one to two feet," he said.

During a normal winter, the ground freezes about six inches and bulldozers can break that crust, Hamp said.

In addition to the frozen ground, the freezing and subfreezing temperatures prevent workmen from pouring concrete, because concrete will not set properly in cold weather.

Even the warm temperatures a week ago were not enough to help, he said.

Two to three weeks of temperatures above 32 degrees are needed to thaw the one to two feet of frozen ground, according to Robert B. Woodward, executive director of the Heavy Construction Contractors Association in Fairfax County.

"We need a minimum of 32 degrees to pour some types of concrete and 50 degrees for other types," Hamp said.

Hamp said he expects the widening of the Beltway from the Cabin John Bridge to Interstate Rte. 95 to be completed "about mid-June," five months behind schedule.

A Metro spokesman said construction work, such as pouring concrete and hot tar and filling large holes at various Metro sites, has been delayed because of the cold weather.

The spokesman, Cody Pfanstiehl, said the construction delays will increase the cost of Metro. However, he said he doesn't know how much the cost will go up since some of the costs due to the weather will be borne by the contractors.

Home builders also have been affected by the cold weather.

"It hasn't been good, that's for sure," said Terrence S. Cook, administrative director of the Northern Virginia Builders Association.

Everett Moone, land development manager for Burke Center, a planned community in Fairfax County, said many of the builders there have had to use a more expensive piece of equipment to break the more than one foot of frozen ground.

The heavier piece of equipment costs between $45 and $70 an hour to operate, Moone said. Normal buildozers average about $35 an hour, contractors said.

Some builders mostly are doing interior work, while they wait for the weather to turn warmer.

Other contractors, like William A. Hazel, Inc., in Herndon, are trying to keep from laying off workers by having employees work fewer hours.

William A. Hazel, owner of the Herndon firm that lays pipes and builds sewer lines, said he has work for only 35 per cent of his 260 work force. He said about 40 of his workers were laid off and are drawing unemployment compensation. The other 220 employees average about 30 hours a week instead of the 40-to-45 hour week they normally work this time of year.

"A lot of these men have been with me for 10 years or longer," Hazel said. "One way or another the guys will get by."

One other construction-related occupation has been affected by the cold weather -- grave digging. At National Memorial Park in Falls Church, diggers have had to use jackhammers to cut through the 30 inches of frozen ground before they can use a backhoe to complete the graves.