英文篇名
THE APPLICATION OF GROUND IMPROVEMENT TECHNIQUES IN THE SOUTHERN SECOND FREEWAY
作者
陳曉明、楊介碩
關鍵字
地盤改良、預壓、垂直排水帶、階段填土
摘要
第二高速公路台南路段所經區域大抵為沖積平原，其沿線地層之分佈主要係由為砂、黏土互層所組成，因受沉積環境之影響土層厚度分佈極不均勻，而地盤軟弱則為其沖積平原所經常遭遇之現象。基於施工成本以及減少長期維護之考量，南二高之路工構造型式採以路堤為主橋樑為輔，是以填土路堤之長期穩定性以及沉陷所可能導致工程構造物間互制問題等，皆為於軟弱地盤進行填土作業其衍生之大地工程問題。地盤改良工法種類很多，各種施工法均具有其特徵與適用範圍，經藉由經濟性、施工規模及對環境保護等各方面之評估考量，決定採用預壓工法為南二高路段之主要地盤改良工法，為縮短預壓時程，乃另配+G37合採用垂直排水帶工法以符合施工時程需求，而由施工過程觀察顯示可達到預期之成效，然因相關監測作業記錄未臻完善，致無法由此作進一步之合理研判與分析，此乃未來須強化之重點。
英文摘要
The terrain along the TAINAN Section of the Second Freeway in Taiwan is mostly alluvial plain, the geological succession of the route is mainly composed of sand and clay. The soil profile around this area changes a lot due to the sedimentation, and the soft ground problem occurs plain very often. Based on the considerations of the construction cost and maintenance task, the type of highway structure in the southern part of the second freeway is embankment mostly, and bridge secondly. Therefore, the long-term stability in embankment section, the mutually constrained problems between different structures resulting from settlement, and so on, are always induced from the filling operation in soft ground.There are several kinds of ground improvement techniques, each kind has its own engineering characteristics and appropriate way to be used. After taking the factors of economy, construction scale, and environmental protection into consideration, the preloading was chosen to improve the original ground situation. In order to achieve the construction schedule, the vertical band drains was also used to shorten the preloading time. According to the observation during the construction period, the expected effect was achieved successfully. But owing to the poorly recording of the instrumentation procedure, further researches and analyses were unable to make, and which should be noted and strengthen in the future.
