The confrontation between the Missouri Portland Cement Co. and its unionized cement workers quickly turned ugly and violent last June 15 when the union refused to accept pay cuts and reduced benefits, and instead went on strike at the southern Illinois plant.

Windshields were smashed. Tires were slashed. Shots were fired at both company and union supporters. Workers who crossed picket lines were harassed and, in several cases, beaten. The company flew in strikebreakers by helicopter, and a union man buzzed the plant in his private plane. Men in Ku Klux Klan garb, on company property, taunted black strikers. Seventeen union members and supporters were convicted of violating court orders.

The weeks of violence in the small Ohio River community of Joppa will be relived today when Sen. Orrin G. Hatch (R-Utah), chairman of the Senate Labor and Human Resources Committee, convenes a hearing on labor violence as part of a Republican effort to expand federal jurisdiction over such strike-related crimes, which are not covered by federal labor law.

The hearing has ruffled Sen. Edward M. Kennedy (Mass.), the panel's ranking Democrat, and Sen. Paul Simon (D-Ill.), who are concerned that it will be a one-sided presentation highlighting union violence and ignoring criticisms of the company's role.

"We will hear testimony about shootings, beatings, property destruction, threats, assaults and wanton disregard for human life," Hatch said in a prepared opening statement. "We will hear how a small town can be traumatized by violence during a strike and how the local judicial process can be turned into a mockery of justice."

Today's testimony -- which is to include Missouri Portland's version of events but not the union's -- will be highlighted by company allegations that strikers and supporters of Local 438 of the United Cement Workers union caused more than $2 million damage and threatened the lives of workers hired as replacements, but went largely unpunished.

The company hired 130 guards -- outnumbering the 115 strikers -- because of what its lawyer, David A. Lang, called the "obvious apathy and political tendencies" of local officials and police, whom the company accused of failing to enforce the law.

The Federal Bureau of Investigation could not enter the case because of a controversial 1973 Supreme Court decision that the Hobbs Act, which prohibits extortion by violence, does not apply to legitimate labor-management disputes in which wages and benefits are at issue.

Union representatives are not appearing at today's hearing because they say they were not afforded sufficient time to rebut nine company witnesses scheduled to testify. Hatch disputed this, saying "the union does not want to have to defend the actions . . . when we have pretty good evidence they violated the law."

Kennedy wrote Hatch last week that he was "concerned that the hearing as presently structured might not be a balanced presentation of all the facts" surrounding the strike. "A limited inquiry by my staff . . . indicates that there is much more to this situation than we were led to believe."

Hatch agreed to a second hearing for the union to present its view.

Union lawyer Jean Souders has acknowledged "one or two serious incidents" of violence involving union members, but said company claims were exaggerated. He said union members believe that Missouri Portland provoked the strike, hiring guards and installing a new security fence and videotape cameras in an effort to "orchestrate" the union's defeat.

Previous efforts to amend the Hobbs Act to cover picket-line violence have failed.