Battering down locked doors, a force of 80 District of Columbia police conducted simultaneous raids on 26 houses and offices around the city Friday, arresting 24 persons in the culmination of an eight-month gambling investigation.

Investigators used telephone registering devices that gave the numbers called from two houses to gather information about what they described as a numbers operation that took in bets at a rate of $10 million a year.

In addition to the arrests, police said they confiscated several guns and a total of $10,000 in cash during the raids, which began at 5 p.m. and were concluded four hours later.

Evidence gathered in the searches is expected to be presented to a grand jury. Two grand juries are currently known to be investigating gambling in the city.

In discussing what they indicated was the voluminous nature of information gathered during the investigation, police said that they prepared an affidavit of 129 pages to support their request for the search warrants authorizing the raids.

In addition to the houses and offices, the warrants authorized the search of four individuals and five automobiles.

Among those arrested, police said, was Walker Johnson, 63, of 1904 Tulip St. NW, president of the Coastline Cab Co., Located at 940 Florida Ave. NW.

Police said both the Tulip Street and the Florida Avenue locations were raided. They said Johnson was charged with operating a lottery.

In a brief interview last night, Johnson told a reporter: "Look, don't pay . . . attention to what you hear. I don't know anything about the gambling. I'm in the taxicab business. I don't know anything about these raids."