Tall fences topped with rolls of barbed concertina wire are giving Fort Chaffee, Ark., the look of a prison camp, as federal officials prepare for the arrival of about 10,000 "hard-core" Cuban refugees from camps in Wisconsin and Pennsylvania.

The intensified security at Chaffee is just the latest symptom of the federal government's continuing problem in trying to resettle the final groups from the flood of 120,000 refugees who arrived in this country in the Freedom Flotilla last spring.

Nearly 13,000 refugees have yet to find sponsors. Meanwhile, federal authorities are nagged by problems with refugees whose sponsorship has failed. Officials say they cannot estimate how many resettlements have failed, but in Miami, a Tent Cit under a freeway is home for hundreds of such refugees.

The remaining refugees in the Arkansas camp have been peaceful in recent weeks, and David Lewis, who runs the U.S. Catholic Conference's sponsorship program at Chaffee, said he is concerned that the beefed-up security measures "may be overkill."

But he said he recognized the local community's apprehensions about the coming wave of refugees -- the difficult-to-place single men from Fort McCoy, Wis., and Fort Indiantown Gap, Pa. Those camps have not been as peaceful.

Just yesterday, Wisconsin Gov. Lee Dreyfus asked the White House to send soldiers to Fort McCoy to break up a refugee-run "security force" that has been charged with rapes, beatings and robberies.

A commission Dreyfus sent to the camp last week to interview refugees concluded that the violence was not "out of control" and was confined to a small percentage of the population there. But the commission recommended that juveniles at the camp be segregated for their protection and that federal authorities dismantle the refugee government.

There have been reports that the Cuban security guards, wearing windbreakers donated by a nearby college, have assaulted their fellow refugees.

Dave Reinhardt, the Catholic Conference's man at McCoy, said yesterday that he was "dumbfounded" to find the Cuban security force when he arrived at the Wisconsin base from another refugee camp at Eglin Air Force Base, Fla. He also said it seemed meaningless to simply transfer the 5,800 refugees from McCoy to Chaffee without having adequate language and job skills programs available at the Arkansas camp.

The Arkansas congressional delegation and Gov. Bill Clinton have been assured by White House aides that they will get to approve the new security measures at Chaffee before the scheduled consolidation of the camp refugees begins there in the next few weeks.

Though the settlement of refugees still in camps -- 12,787 at last count, including those at Chaffee -- is the most visible problem, the problem of failed sponsorships is becoming increasingly troublesome.

Miami's Tent City is a highly visible reminder of the failure of some resettlement efforts. An official of the State Department's Cuban-Haitian Task Force said yesterday that the facility will be phased out in the next month. The city of Miami health department recently cited the camp for numerous violations of health and sanitation laws.

Refugee officials said they could not estimate how many sponsorships had been broken, though there are about 80,000 Cuban refugees in the Miami area and about 4,000 who have moved through Tent City.

Reinhardt, of the Catholic Conference, said he was surprised at the number of family members who have rejected relatives from Cuba.

The recent rash of hijackings back to Cuba by disgruntled refugees has not helped the newcomers in the area of public opinion, officials acknowledge. And that support is needed, in Congress especially, to finance the benefits the settled Cubans need while adjusting to their new society.

When the Carter administration announced its refugee policy June 20, it didn't agree to full federal financing of benefits. But members of the Florida congressional delegation moved quickly to reverse that.

A $100 million appropriation to fund full benefits for the Cubans was quickly passed, but the necessary authorization language to permit its spending has not yet been passed.

Financing is also a chief topic of conversation for the voluntary agencies trying to find sponsors for the Cubans. John McCarthy, head of refugee services for the U.S. Catholic Conference in Washington, which has settled the majority of the Cubans, said he is troubled by the lack of government funding for his effort.

He said the lack of education, language and job skills in the remaining group of single, male refugees means his agency will have to find and pay for full-time counselors to work with clusters of four or five men as they move into local communities. "That is going to cost me real dough," he said.

Yet another problem facing the administration is the fate of the 1,600 hardened criminals who have been weeded out of the population and are facing deportation proceedings. About 165 have already been ordered to leave, but so far there is no sign that Cuban President Fidel Castro will take them back, so they remain in federal prisons.

Art Brill, a spokesman for the State Department task force in Washington, said yesterday that the chief concern is the McCoy population, which includes 950 mental cases. "That's a very difficult population there," he said.

"The last thing we want to do is make a prison [of Chaffee], but we're not running a country club either. It's a shame about the bad apples because there are a lot of good people still there and they're being robbed by the same cloth."