Pile-bottom grouting cavity and method for using same, and cast-in-place pile body and method for constructing same

A pile-bottom grouting cavity, comprising:

• a grouting capsule having an expansion state in which an interior of the grouting capsule is filled with grout to bear a pile body, and a contracted state in which an interior of the grouting capsule is hollow;
• a grouting pipe communicating with an inner cavity of the grouting capsule for grouting the grouting capsule;
• and
• a fixing plate provided with the grouting capsule thereon, and a through hole therethrough, wherein the through hole communicates with a bottom of an accommodation hole for allowing slurry and/or sediment within the accommodation hole to pass through the through hole of the fixing plate;
• and
• a grout replenishing structure, communicating with the through hole for grouting into the through hole, and/or, the grout replenishing structure comprises at least one grout replenishing tube which is communicated with the through hole for grouting into the through hole;
• wherein the grout replenishing tube comprises a second grouting portion extending into a cavity of the through hole and is provided with a plurality of second grouting holes, and the second grouting portion comprises an annular pipe extending along the contour of the hole wall of the through hole;
• or the fixing plate comprises a grout-storage chamber communicating with the through hole, and the grout replenishing tube communicates with a grout inlet of the grout-storage chamber.