| Summary: | 碩士 === 國立中興大學 === 水土保持學類 === 84 === The purpose of this paper was going to measure the total
shear stress in order to understand the flowing characteristics
of debris flow. Twenty-one kinds of soil materials which were
composed with different grain size were used to conduct the
flowing experiments in flume channel. And the results were
concluded as follows: 1. A shearmeter which was made with
strain gage could measure the total shear stress during
debris flowing. But the output signals still could not regulated
perfectively because of the restriction of recorder. 2. The
bore height is an important factor to affect the shear stress in
debris flow.Measured shear stress would increase with the
bore height, so does the volumetric concentration. 3.
Velocity had an inverse tendency to the measured shear stress.
The velocity gradient might be play the main role rather
than the velocity to affect the shear stress. 4. In the
viewpoint of dynamic friction, the inner dynamic friction
cofficient would increase with H/D50 and the flume channel
slope but in inverse of the volumetric concentration. For
the surface friction of shearmeter, the friction cofficient
would have the inverse tendency to H/D50 and the flume channel
slope. 5. Comparing with Takashi''''''''s velocity equation, Yu''''''''s
equation might comparatively match with the measured
velocity. The measured velocity could not match well with
the theoretical velocity, because some parts of observations for
flowing velocity were not in the state of steady flow. 6.
Synthetic roughness on the channel bed made the shear stress
higher than the theoritical shear stress. The observed shear
stresses could not confirm whether the real shear stress
was or other stress effects were contained.
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