(portal steel structure housing CECS102:2002), there is a column foot according to the friction system calculation, such as does not meet the requirements of shear should be set up shear key, friction coefficient according to 0.4 considerations, the formula for ≥ 0.4N (need to be set up); Q ≤ 0.4N (do not need to be set up), there is also an important condition, the second pouring to be dense, and the concrete should be added with an expander!