臺灣之地震頻繁,地質狀況破碎複雜,且位處颱風頻仍之亞熱帶地區,隨著經濟迅速發展,坡地開發日益增加,台灣大部分縣市均面臨坡地崩塌災害之威脅。水是各種山坡地問題的主要原因之一,而水的來源主要來自降雨,台灣雖年降雨量豐沛,但伴隨季節、位置、海拔的不同,降雨量亦隨之變化,因而造成降雨時間及降雨空間極不均勻,對山坡地所造成之影響相當大。本研究首先以小型砂箱模型試驗,探討不同土砂配比的崩塌破壞模式、土壤水份及試體飽和度,進而選定符合經降雨入滲破壞之試驗條件;再以大型砂箱來進行試體位移之崩塌破壞模式、試體飽和度、孔隙水壓值及坡體位移等關係。研究結果顯示,不同降雨強度對土壤滲透係數會促使崩塌破壞模式有所影響,其改變幅度會隨著降雨強度高低而有所變動。降雨強度遠大於土壤滲透係數時,其破壞型態以淺層滑動為主;降雨強度近似於土壤滲透係數時,則主要為較深層滑動;若強雨強度小於土壤滲透係數時,則主要為飛濺沖蝕。飛濺沖蝕時試體飽和度介於45~48%,其位移速率較慢,為5.0×10-4cm/s;深層滑動時其試體飽和度介於76~79%,其位移速率較快,約9.2×10-2cm/s;而淺層滑動時試體飽和度介於62~66%,其位移速率介於前兩者之間,約為6.7×10-3cm/s。
There are many damage factors in Taiwan, indude frequent earthquakes, broken complex geological conditions, frequent typhoon and weather subtropical. With economy rapidly development, slope development growing increasing, Taiwans counties are facing the threat of landslide hazard. Water is the one of key factor on slope stability, rainfall is the main source of water. Taiwan although annual rainfall rich, but the rainy season, location, and altitude different all induced the large impact to hillside. This study a searier of sand model to explore the behaviors on performs landslide damage mode, soil moisture, and specimen saturation, pore pressure and slope displacement. As the resulf shown, rainfall intensity much larger than soil permeability, the failure patterns in shallow landslide. Rainfall intensity close to soil permeability is mainly caused the more deep sliding. As rainfall intensity lower than soil permeability are mainly induced the surface erosion . Learned test after, failure of the specimens saturation between 45 to 48%, the displacement rate of 5.0×10-4cm/s; deep slide of the specimens saturation is between 76 to 79%, the displacement rate of 9.2×10-2cm/s; last shallow slide of the specimens saturation is between 62 to 66%, the displacement rate of 6.7×10-3cm/s.