The　long-term　deformation　of　a　17.5　m　deep　excavation　constructed　with　the　bottom-up　technique　in　silty　clay　in　Xi＇an　was　monitored　in　this　study.　The　retaining　wall　was　built　with　one　or　two　rows　of　contiguous　bored　concrete　piles　and　tie-back　prestressing　tendons.　The　monitoring　of　settlement　and　lateral　deflection　at　the　top　of　the　retaining　structure,　and　the　settlement　of　the　ground　surface　and　of　the　adjacent　building　lasted　for　more　than　4　years.　After　the　final　depth　was　reached,　the　excavation　was　surveyed　for　more　than　3.1　years.　It　was　observed　that　the　deformation　of　the　excavation　increased　with　the　increase　in　the　excavation　depth,　and　a　significant　increase　in　displacement　was　recorded　after　the　excavation　reached　the　final　depth.　The　averaged　time-dependent　rates　of　the　deflection　of　the　retaining　wall,　and　the　settlement　of　the　ground　surface　and　of　the　adjacent　building　when　the　excavation　remained　partially　unfilled　were　around　0.23-0.25　mm/month　in　this　study.　The　time-dependent　behavior　of　the　excavation　could　lead　to　excessive　deformation　and　cause　severe　safety　risks　to　the　retaining　system.　The　recorded　data,　together　with　a　comparison　with　cases　reported　in　the　open　literature,　are　presented　in　this　paper.