Construction work has finally begun on the new Soviet Embassy in Washington. Bulldozers have started clearing trees and dense patches of weeds from an upper Northwest site at Wisconsin Avenue and Calvert Street.

The bulldozers began their task Saturday after nearly 15 years of negotiations between the Soviet and American governments.

Pursuant to agreements signed in 1969 and 1972 between the two superpowers, construction work on both new Soviet Embassy here and on a new U.S. Embassy in Moscow was supposed to have begun simultaneously.

However, according to State Department spokeswoman Dixie Grimes, American engineers encountered technical problems with the site chosen by the United States in Moscow.

"We are now scheduled to begin work on our embassy in Moscow next May," Grimes said, "and we gave the Soviets permission to begin early on theirs in an amended version of our agreement."

According to a spokesman for the Soviet Embassy, the new Soviet complex here will include an eight-story chancery, a nine-story apartment complex, a school for Soviet children, and recreation facilities housing a swimming pool and gymnasium, all of which will be situated on 12 1/2 acres of land.

"Construction will probably take four to five years to complete," the Soviet spokesman said.

Since 1933, when the United States first recognized the Soviet Union, the Soviet Union, the Soviet diplomatic force in D.C. has increased tremendously. Now, with approximately 500 persons assigned here, the Soviet Union's is the largest embassy in Washington.

Currently, Soviet government offices are scattered all over the capital. After its new embassy complex is completed, Soviet housing facilities and diplomatic services will be located largely in one plave.

Soviet planners of the new embassy here have estimated total construction cost at $70 million.

The Soviet Union's present embassy, located a few blocks from the White Houseat 1115 16th St. NW, will be retained as the ambassador's residence.