How many Lbs are there in a yard?

A pound (Lb) is a unit of measurement for weight while a yard is a unit of measurement for distance.
If you are referring to common measurements used on a construction site, a “yard” is a common abbreviation for a “cubic yard”, which is a unit of measurement of volume. (A cubic yard equals 27 cubic feet.)
Since dirt weighs about 110 pounds per cubic feet, a cubic yard of dirt weighs about 2970 Lbs. Since concrete is heavier (150 PCF), a cubic yard of concrete weighs about 4050 Lbs.