萬丈高樓平地起－－國立科學工藝博物館之反循環基樁工程

A Solid Foundation for an Imposing Structure: The Reverse Circulation Piles for the Foundation of the National Science and Technology Museum

萬事起頭難，尤其是建築物的基礎，在無法完全掌握地質的情況下，施工品質的優劣及檢測的是否嚴謹，關係著該建築物的安危。國立科學工藝博物館因造型及使用性特殊，使得結構亦較一般傳統建築複雜。為使該館屹立百年而不倒，因此在結構體方面採鋼骨結構系統，在基礎方面則採筏式基礎，且於筏式基礎下，使用多達六百餘支之反循環基樁，其中有深達岩層（泥岩）之承載樁，亦有為抵抗水浮力之抗拔樁。載重下的樁行為，常受多項變數影響，因此基樁工程在設計階段，大都要做現場試樁載重試體，用來檢核樁的估計承載力與幫助建立打樁的規範，或用來檢核樁的承載力是否達到契約中規定的標準。本工程共施做了八組基樁載重試驗，均達到原設計之要求。本工程使用S-400型鑽機型六百餘隻不同樁徑及樁長之基樁，前後施築達十個月。本文將就國立科學工藝博物館基樁設計經過、基樁載重試驗、施築過程等做一研究檢討，或可做為國立科學工藝博物館建築工程之紀實。

The National Science and Technology Museum was constructed using a steel frame and mat foundation . Under this foundation are more than 600 reverse circulation piles, many of which are driven all the way down to bedrock below the site. There are also rows of piles designed to keep ground water from seeping into the site. The foundation piles with the heavy loads are subjected to many different stresses, which means it is necessary to conducts a number of load-bearing tests on-site to check the strength of the foundation and help plan the layout of the piles. These tests ensure that the foundation will be stable and meet the specifications called for in the construction contract. Eight different kinds of tests were conducted during preparation of the foundation for this project, and all were passed by wide margins. Altogether it took nearly ten months to put the 600 piles for the site into place. One of the key tools used to check the foundation during this period was ultrasonic testing.