The Corcoran Gallery of Art's 21st Area Exhibition - this year, by design, limited to sculpture - might as well be signed by a single personality, our increasingly familiar friend the curator-as-artist. This survey exhibition, an admirable effort, is Maurice Tuchman's show.

Tuchman, senior curator of modern art at the Los Angeles County Museum, is as are the local sculpture he admires - a sophisticated, highly schooled, moderist professional. He was the exhibit's one-man jury. He took the time to study nearly 700 sculptures, then admitted 27. Tightening his scrutiny, he gave three of these cash prizes.

He is not a wishy-washy fellow. His show is not inclusive or kindly democratic, nor is it chaotic. It is more thoughtfully considered than, say, the average Whitney Annual. It is an honorable exhibit in an academic mood.

The word "academic" used to be a putdown, implying the dredged-up, the stale and the fussy. It has another meaning now.

This Area show is studious, but not at all old-fashioned. Art historians of the future, leafing through its catalogue, will have no trouble dating the well-made objects shown to the last years of the '70s when the Idea of Newness was still a central canon of high, official art.

The newness of this show is not the newness of '60s. These objects do not shock, instead they demonstrate and teach. The 27 sculptors are not self-indulgent. They do not improvise or wing it. Some of them weld steel, some pour concrete or plastic, some join lengths of wood, and they know what they are doing.

They are erodite. Their works of art do not rely on scatterings or chance, nor do they confront us with minimalist blankness. Not all of them, but most of them, load their work with references to the concerns, and stars, of contemporary art.

"The Mickey Mouse Mummy" of Nil Felts amusingly alludes to Disney, Oldenburg and Dine, much as the "Accident Investigator Trench Costs" of J. Blevins Kirby (one, for daytime wear, made of sheet aluminum; the other, for the evening, tailored out of tar apper) as wittily suggest Dashiell Hammett's macho tough guys and the bathrobes of Jim Dine.

A number of these sculptures intentionally tell stories. "A Solemn Shoeshine Service" by Vanessa Guerin seems a shoe fetishist's heaven. It is an enclosed room-size environment in which pairs of shoes are placed on chairs or on an altar, amid silver bowls and candles, but never on the floor. This work recalls McGowin's autobiographical tableaux, and its pseudo-sacred hush seems broken by the imagine snap of the shoeshiner's rag.

References to other well-known sculptors dart throughout this show. Daniel Geier's piled blocks of concrete bow to Robert Morris and Carl Andre. Tuchman notes correctly that John McCarty's "cannily knowing" sculpture is "unthinkable without the example of David Smith and Caro, but it is winningly sophisticated and deft in these items."

Hildegarde van Roijen, Janos Enyedi, and Nick Ward - all of whom work steel - use a similar vocabulary. So does David Station, though he works with rough-hewn wood. Caro's art is in.

Many of the sculptors here are not at all well known. Not yet. This screened, selective show will enhance reputations.Tuchman gave six prizes. And the winners are:

First prize, $1,500, to "Curved Space" by Nade Haley, a 30-foot long wall of subtly worked red oak. The second prize, $1,000, went to David Logsdon's "X Square," a set of eye-engaging wooden gates made of old used pine. McCrty's "Rialman" won $750.Christopher Gardner's "Second Stage," a bright red complex pyramid; Stephen Ludlum's outdoor zigzag fence, and V. V. Rankine's "Stand," a wall piece that seems part figurative part abstract, part scupture and part painting, all received honorable mentions from Tuchman.

I, too, like these pieces, though "Quadrant" by Jim Sanborn, Tad H. Wanveer's forest figures of old wood and peat moss, and particularly Watson's horrific composition, with its heron and its Ilama, both growing out of pipe cleaners, seem to me as strong.

Tuchman writes: "This exihibition of art from the Washington area is not a knockoff of last month's Artforum . . . I'm certain most colleagues of mine would expect, as I did, to encounter scores of sculptures that derive from the resurgent constructivism, the new plastic surrealism, yet more minimalism, and lots of photographic video-taped conceptualism . . . Not so."

Many may find Tuchman's eye scholarly and formal but his taste is far from narrow. He has included works both huge and tiny, frightening and funny, both delicate and tough. Some are painted, most are not. A few of them are playful; Sara Yerkes' "Window Machine," with its wheel and its sails, seems a sculpture one could ride. Others seem, in contrast, almost antiquarian; Elizabeth C. Falk's life-size bas-relief seems closer to the Renaissance then to 1978.

When the Corcoran announced that this year's Area show would examine local sculpture, "The experts," says Peter Marzio, the gallery's director, "told us to expect disaster."

The "experts," mostly dealers, prefer to stick to paintings. Sculpture is difficult to move, to store and of course, to sell. Nevertheless there are scores of gifted sculptors working in this area.Not all made this show, yet, by implication, this exhibit honors all of them. Marti Mayo, who shepherded the project, figures that it cost the Corcoran almost $50,000. The money was well spent.

Those who doubt the Corcoran's commitment to the Washington area, the liveliness of modern art or the power of new sculpture ought to see this show.