The aluminum pieces of the giant tent that will house Wolf Trap Farm Park's upcoming summer performances arrived here at 6:30 yesterday morning on the last leg of a journey from the United Arab Emirates.

After the cargo arrived at LaGuardia Airport in New York Friday night, workers loaded the 45 tons of aluminum truss arches onto four flatbed trucks for the trip to Virginia. "They look like parts of an Erector Set," said Wolf Trap public relations official Larisa Wanserski. Saudi Arabian Airlines is paying the estimated $100,000 in shipping expenses from the U.A.E. to Wolf Trap.

Catherine Filene Shouse, founder and donor of Wolf Trap, was not present to see the trucks unloaded because of a hip injury she suffered in a fall Sunday evening at her home in Easton, Md.Yesterday she was in "minor traction" at Sibley Hospital.

Workers began unloading the bales of aluminum onto the parking lot behind the stage house area at 7:30 a.m. and were finished four hours later, according to Will McIntyre, regional manager in the Denver office of Sprung Instant Structures, which manufactured the structure. Next, the pieces must be washed and examined.

"We're starting assembly tomorrow," said McIntyre. "We're anticipating an erection date of the 20th and we're anticipating completing construction by the 27th."

The first of two shipments of fabric to tent the structure is expected tonight, according to McIntyre. The second is due within a week. The tan-colored fabric is being shipped from Sprung Instant Structure's Calgary, Alberta, office.

"The color of the fabric in Dubai wasn't suitable," said McIntyre, "and we were trying to cut down shipping weight and cost."