五層樓淺基礎建築物受震液化反應-離心模型;nono

NCUIR > Engineering College > Graduate Institute of Civil Engineering > Electronic Thesis & Dissertation > Item 987654321/84846

Please use this identifier to cite or link to this item: http://ir.lib.ncu.edu.tw/handle/987654321/84846

Title:	五層樓淺基礎建築物受震液化反應-離心模型;nono
Authors:	邱義宏;Qiu, Yi-Hong
Contributors:	土木工程學系
Keywords:	淺基礎;土壤液化;離心模型;沉陷量
Date:	2020-10-28
Issue Date:	2021-03-18 16:28:57 (UTC+8)
Publisher:	國立中央大學
Abstract:	台灣位於環太平洋火山地震帶，土壤液化經常伴隨地震而發生。於921大地震時，受到液化引致基礎沉陷與承載力破壞是淺基礎損壞的主要原因。本研究設計五層樓高(16m)之建築物模型，搭配四種不同形式基礎，包括大獨立基腳基礎、小獨立基腳基礎、筏式基礎與地下室基礎，利用中央大學地工離心機與震動台於65g重力場環境進行離心模型試驗，砂土試體中不同深度埋置加速度計、孔隙水壓計、線性差動變壓器(LVDT)、雷射位移計及土壓力計，分別量測地層各物理性質之動態歷時反應，探討淺基礎建築物於液化地盤上受震反應。研究結果顯示，當土壤未達液化時，地盤加速度有放大趨勢，隨著建築物越高加速度放大效應越明顯；但當土壤達液化狀態時，液化土層能有效阻隔震波向上傳遞，對於建築物有明顯地減震效應；施加震動強度越大，液化土層深度越深，超額孔隙水壓消散所需時間也越長久；在自由土層中，大部分沉陷主要由震動期間而發生；建築物沉陷由震動過程土壤受剪力作用而引致變形與超額孔隙水壓消散後土壤再壓密;基礎版之總應力歷時發現於受震初期，基礎版一端受壓時另一端受拉，底版總應力隨著建築物沉陷而持續累加。 ;A series of centrifuge tests were performance to investigate the settlement and seismic behavior of building on liquefiable ground with different types of foundation. The test were carried out by using NCU centrifuge and shaking table under 65g centrifuge acceleration field with liminar container. During the test, accelerometers, pore pressure transducers, linear variable differential transformers (LVDT) and laser displacement sensor were embedded in the soil layer to monitor the seismic response of soil deposit. The centrifuge experiments were conducted to evaluate the liquefaction-induced and post-liquefaction settlement of shallow foundations. According to the test results, the following conclusions are made : When the soil does not liquefy, the acceleration is amplified significantly from the base of soil stratum to the top of structure. In liquefiable ground, liquefied layer will isolate the vibration that propagate to the buildings. The liquefied depth of sand layer increases with the increasing of input. In the free-field ground, most of the settlement occurred due to volumetric-induced deformations; In contrast, foundation settlement occurred due to shear-induced deformations and excess pore water pressure dissipate.
Appears in Collections:	[Graduate Institute of Civil Engineering] Electronic Thesis & Dissertation

Files in This Item:

File	Description	Size	Format
index.html		0Kb	HTML	126	View/Open

社群 sharing

Loading...