Answer: I too had the same problem you describe. My basement floor was poured in two sections with a cold joint running the length of the basement, about 24'. I live in a river bottom at the edge of a slough that fills with water when we have high river stages. Occasionally the water gets so high as to put pressure on the basement floor and leaks in through the cold joint. I put a 16"diameter X 24" deep sump at one end of the cold joint in my utility room. I actually cut about a 30"+ hole and probably that deep so I could put some concrete in the bottom to hold the sump level and to get the correct height for a sloped edge from the floor level to the opening of the sump. The sump has 4 2" close pipe nipples welded evenly spaced around the top of the sump with 90 deg. elbows and short nipples pointing straight down on the outside. I poured and packed the area around the sump with washed pea gravel then concreted the top in a slope as mentioned above. On the inside of the sump I used 2" union halves and used stainless steel mesh cut to fit inside the union nut with a home made rubber washer on each side of the mesh to hold it in nicely. The mesh is to keep debris out of the sump if any ever gets through the pea gravel. The water has only been up high enough to put water in the sump twice since I installed it. Water runs into the sump via the four penetrations and relieves the pressure on the floor. Both times, the floor remained dry. I just use a run of the mill submersible sump pump and discharge it to the floor drain.