The U.S. Senate, which has passed legislation forcing public buildings all over the country to remove barriers to the handicapped, is facing an embarrassing problem.

It has a new member coming -- Sen. elect John East of North Carolina-- who is confined to a wheelchair and the Senate is only partially accessible to the handicapped.

A person in a wheelchair can get into the Senate chamber, for example, but without assistance cannot get to desks at which senators sit, nor into the clubby atmosphere of the Senate cloakroom.

Similarly, a person in a wheelchair can reach Senate committee hearing rooms, but with the exception of a few committees where ramps have been installed cannot get onto the lofty daises where senators and key aides sit.

The wheelchair-bound can travel between the Capitol and Senate office buildings by underground tunnels, but not on the subway cars, and the trip by wheelchair is a long, arduous climb up a gradual incline.

The Senate has also installed special restroom facilities for the handicapped, but only on the first and fourth floors of the Senate office buildings.

People in wheelchairs do get about the Capitol, and occasionally a senator recuperating from an operation or a ski accident has had to share their experience. There also is a $2.7 million project under way to make the Capitol barrier free.

But this project won't be completed until 1982 or later, and wheelchair users who frequent the Capitol complain they get around only with difficulty. "Things are not real good. I find there are steps everywhere," says John Lancaster, an attorney for the American Coalition of Citizens with Disabilities. "You can get around on a wheelchair if you're good at it. But only if you're good."

The Senate, he adds, has not lived up to the spirit of the laws it passed.

All buildings constructed with federal funds have been required to be accessible to the handicapped since Congress passed the Architectural Barriers Act in 1968. And since the Rehabilitation Act of 1973, any agency of firm that receives more than $2,500 a year in federal funds has faced the prospect of losing those funds if programs aren't accessible to the physically handicapped.

Sen.-elect East apparently isn't too worried about getting around the Capitol. "There were really very few problems when we were in Washington for Senate orientation a couple of weeks ago," said East campaign director Ann May.

Capitol architects have decided only two major renovations will be necessary for East, a political science professor from East Carolina University, who has been confined to a wheelchair since he had polio almost 25 years ago.

They are planning to build a modest lift device so he can get up the three steps into the Senate cloakroom, and are putting a specially fitted toilet off the cloakroom. The cost is to be about $10,000.

Architects also considered putting a ramp on the Senate floor to enable East to move up and down the chamber aisle, according to Elliot Carroll, executive assistant to the Architect of the Capitol. But that idea was rejected when it was found the ramp would be too steep to maneuver up and down. r

East, like all freshman senators, will sit in the back row of the chamber. And if he wants to get to the well of the Senate he will have to do so by a roundabout route, going outside the chamber and entering from a different door.