The pilot reported that during arrival, he followed the ILS glide slope to touchdown about 1000 ft down the runway. He reported the landing was smooth, and when the aircraft was approximately 100 ft from the intersection of runways 1/19 and 10/28, he saw a ridge of snow and ice across the runway. Since the aircraft was still traveling at approximately 50 knots, the aircrew could not avoid the ice and snow. As the aircraft crossed the intersection, a loud noise was heard. The landing gear aural warning horn activated and the red light on the nose gear indicator illuminated. After stopping, an inspection revealed the nose gear was bent aft and the fuselage was wrinkled. Also, the space between the nosewheel tires was found packed with ice. A further investigation revealed that snowplow operators had been plowing snow on runway 10/28 and turn-arounds had been made on runway 1/19 before the Swearingen, N1011N, had landed.