The Army said yesterday it is studying proposals to move Fort Belvoir's combat engineering operations to Missouri, a shift that could force the eventual relocation of some 1,200 military personnel now assigned to the base just south of Mount Vernon.

The six-month study, which the Army plans to announce today, will look at the feasibility of transferring Belvoir's engineering center and a company of combat engineers to Fort Leonard Wood, Mo., by 1987. The idea has been broached before, only to encounter heated protests from Virginia officials.

"I thought this snake had been killed two years ago," said Rep. Stan Parris (R-Va.), whose district is home to the 9,200-acre base. He argued that the proposal "totally and completely ignores" the concerns of Belvoir-assigned civilian and military personnel who live in Northern Virginia and may not want to move to Missouri.

An Army spokesman stressed yesterday that the proposed relocation is only under study, but he said the Army estimates that the transfer, along with the consolidation of the U.S. Army Intelligence and Security Command, could save the military about $14.4 million annually.

In addition to saving money, however, the overall consolidation plan might make the relocation more palatable to local Virginia officials since it would replace the lost engineering operations with other Army functions. About 1,108 persons from the Intelligence and Security Command, drawn from Fort Meade and Arlington Hall Station, would be moved to Fort Belvoir if the Missouri transfer takes place.

The Army has been discussing such consolidation for several years. The Army is required to notify Congress of the transfer, though its approval is not required. Army representatives visited some Virginia congressional officials yesterday to explain plans for the study.

Parris, after meeting with Army officials, remained unconvinced. He said he was skeptical that the Army would really replace the lost engineering jobs, and he questioned whether the estimated savings would be achieved.

"I just think the human impact and the insensitivity of these kinds of decisions need to be considered more," Parris said.