地聲探測器應用於土石流之初步研究

A Preliminary Study of Detecting Debris Flows by a Geophone

10.29417/JCSWC.199912_30(4).0003

劉格非(Ko-Fei Liu)；李欣輯(Hsin-Chi Li)

地聲探測器 ； 土石流 ； geophone ； debris flow

中華水土保持學報

30卷4期（1999 / 12 / 01）

263 - 272

繁體中文

本研究利用地聲探測器分別在室內及野外做了多組的試驗以測試其探測土石流之功效。在室內渠槽實驗部份，是以細砂石（3～5mm）來模擬土石流的流動。我們從坡度、砂石量及流量設計了多組實驗，從各組實驗結果分析中發現，以細砂石來模擬土石流滾動的頻率分佈大約是在40～50Hz之間。同樣在野外實驗部分，我們亦設計多組實驗，分別在野外及砂石場以各種不同粒徑的石頭來測試，利用石頭滾動及互相撞擊的頻率來模擬土石流的流動時大小石頭滾動及互撞所發出的頻率。結果發現土石在以石頭滾動及互相撞擊產生的聲頻分佈是在40～80 Hz之間。綜合室內及野外的實驗結果，可知石子滑動之頻率分佈是在20～30 Hz間，石頭互相撞擊之特徵聲頻是集中在50 Hz左右，且無論砂石之粒徑爲何，所測得之頻率分佈大都在20～80左右，且以40～60居多。我們可以初步判定土石流流動的特徵頻率大約是在40～60 Hz左右。

The feasibility of using geophones on debris flow detection has been studied experimen tally. We use fine sand (3~5mm) to simulate debris flows in flume tests with varying slops, sand volume and bottom roughness. The characteristic frequency range of debris flows from flume tests is found to be between 40~50 Hz. Different sands and stones are used in the field experiments. A tracker shovel is used to push piles of sands. The motion of rolling and collision of stones is similar to real debris flows. The characteristic freqeuncy range in the fields is found between 40~80 Hz. Analyzed results show that the frequencies of sliding of sands or stones is between 20~30 Hz. The frequencies for rolling and collision are between 50~60 Hz. These conclude that the characteristic frequency range for debris flows are between 40~60 Hz.