摘要(英) |
For
the experiment designed by this research, we enhance the flow
concentration through the change of cross-section to control the
core of water flow, reducing the risk of debris flow overflow
and accelerating its passing through the protected area. With
the on-site matching simulation of such three cross-sections as
rectangle, trapezoid and V-section through the equivalent weight
replacement approach, this experiment proceeds the experiment of
indoor debris flow flume by controlling various conditions
respectively including different volumes, different volume
concentrations and different maximum grain sizes to study the
influence of channel cross-section change on debris-flow moving
and deposition situations.
With the statistics of data including velocity, deposition
distance, width and depth, the result shows that the channel
cross-section configuration will influence the state of debris
flow and its deposition range. The velocity of V-shape flume is
higher than that of trapezoid and rectangle flumes. Both of
deposition length and width resulted from the V-shape flume
drainage of debris flow are the biggest, whereas they are the
smallest for the rectangle flume. It is evident that the
conical-bottom flume is better to control the core of debris
flow, which is beneficial to channel and conduct the debris flow
to a safe area, than the flat-bottom flume. This research
established a human-tested empirical regression formula before
the-modification of shape factors. After the shape-factor
modification of such empirical formula, we find that the
accuracy for the result of rectangle, trapezoid and V-shape
flumes is 91.1%, 78.2% and 90.2% respectively by comparing the
estimated debris-flow deposition length of the empirical formula
with that of the experiment. |