Guide tolerances during elevation of the jack-up rig will（）.

A.reduce spud can bearing pressure

B.keep the unit level and reduce overloading

C.reduce stresses on the hull

D.minimize the potential for punch-through

钢网架结构总拼完成后及屋面工程完成后应分别测量其挠度值，且所测的挠度值不应超过相应设计值。