To provide an impermeable sand control dam using a steel pipe structure and a method for constructing the sand control dam by assembling the structure manufactured in a factory at a job site by rationally designing and standardizing the structure suitably for assembling at the job side such as a mountain district according to a scale of a predictive disaster.

This large diameter steel pipe sand control dam 100 is composed of a large diameter steel pipe body 10 for connecting a large diameter steel pipe unit 11 divided into a plurality in the lengthwise direction by a joint 12, an upstream side steel pipe anchor beam 20 fixed to the flowing water upstream side of the large diameter steel pipe body 10 and packed with concrete, a downstream side steel pipe anchor beam 30 fixed to the flowing water downstream side of the large diameter steel pipe body 10 and packed with the concrete, a wheel unit 40 installed in a lower part of the large diameter steel pipe body 10, a rail and a sleeper assembly 50 for supporting the wheel unit and the concrete 60 made to flow in a lower space of the large diameter steel pipe body 10. An intake port 111 and an exhaust port 112 are arranged in a prescribed place of the large diameter steel pipe body 10. Flowing-down water is introduced into the large diameter steel pipe body 10 from the intake port 111, and a vertical load can be increased.