Tōng / guò / bù / duàn / wā / tǔ / chén / jǐng / màn / màn / xià / chén / dào / shè / jì / shēn / dù通过不断挖土,沉井慢慢下沉到设计深度。By continually removing soil, the open caisson gradually sank to the designed depth.