The invention discloses a construction method for blocking a depressurization well by adopting accelerated
cement. The construction method includes the step 1, filling a filter
pipe on the bottom of a well casing with the accelerated
cement after
precipitation and before well blocking, step 2, blocking gaps around the filter
pipe after the
cement hardens when meeting underground water in the casing and after the cement seeps into the filter
pipe, step 3, pumping residual water in the well casing out after the cement reaches initial
setting time, step 4,
welding two
layers of
water stop steel plates outside the well casing, step 5, carrying out primary microdilatancy concrete pouring and smashing in the casing when the
water level on the bottom of the casing does not rise obviously after the cement sets and hardens in the bottom of the casing, step 6, guaranteeing that
water seepage does not exist below a casing mouth,
welding short steel bars in the plane, placing a
flange ring, and carrying out full weld on the portion, above the ring face and the portion, around a casing wall, step 7,
welding and sealing the
steel plates fully on the upper portion of the
flange after full-weld is carried out on the
flange, and then carrying out secondary microdilatancy concrete pouring in a high casing until the casing mouth face is flat, and step 8, pouring the high casing and a bottom plate to a bottom plate structural face after well blocking is completed. According to the construction method, operation is quick and convenient, well blocking periods are short, cost is low, and the construction method can be applied to later-stage different water yield situations of the depressurization well in a pit.