人造軟岩沖蝕率試驗研究

Abstract

影響軟岩沖蝕的因子與機制眾多，本文就水力沖蝕機制之觀點進行研究，藉由改變人造軟岩試體強度進行水槽試驗，以探討強度對於軟岩沖蝕率之關係。

依據本實驗之結果，嘗試找出人造試體在各強度下對應之沖蝕臨界條件。臨界條件之決定，係藉由流速與平均沖刷速率之關係圖，藉由回歸方式得之，在回歸線上平均沖刷速率為零時，即定此時流速代表為臨界起動流速。於本文中將平均沖蝕率與流速之關係以乘冪形式回歸，發現具有良好之關係性。

Rock erosion has several kinds of mechanism which are complicated. The erosion rate are affected by many factors. To make it simple, this research focused on hydraulic type of erosion and tried to find the relationship between rock strength, flow velocity and erosion rate . A series of experiment and equipment is designed and established. Since it is difficult to collect sample from the field, the test samples used in the experiment are artificial , and the material is made of plaster and bentonite as a mixure.

The critical condition is determined based on McNeil(1996); it is specified by the regression line on the plot of erosion rate and flow velicity, where the intersection with the velocity axis means the average erosion rate is equal to zero, and thus is defined as the critical velocity.