Control and Interception Characteristics of the Debris-Flow Flexible Net Barrier Based on Orthogonal Design

Abstract

As a debris-flow control and mitigation countermeasure, flexible net barriers can effectively mitigate debris flows. The control and interception characteristics of flexible net barrier play an important role in engineering design. Many influencing factors exist in debris-flow flexible net barrier control and interception processes. In order to explore the most important factors, a flume-based experimental study was carried out by selecting the four main factors, i.e., the flume slope, debris flow bulk density, net barrier interval and relative volume. The purpose of the study is to analyze the influencing degree of the four factors. Moreover, the debris-flow interception ratio, blocking ratio, velocity reduction ratio and bulk density attenuation ratio are taken as the evaluation index. Based on the theory of orthogonal experimental design, the experiment results were analyzed in detail by range analysis and variance analysis. The research results indicated the following: in regard to the interception ratio, blocking ratio, and velocity reduction ratio, the net barrier interval exerted the most notable impact, followed by the bulk density. In regard to the bulk density attenuation ratio, the flume slope and bulk density were the first and second most important influencing factors, respectively. The form of interception ratio with maximum value was as follows: the flume slope was 9°, the net barrier interval was 18 mm, the bulk density was 21 kN/m3 and the relative volume was 2/3. The form of blocking ratio with minimum value was as follows: the flume slope was 6°, the net barrier interval was 50 mm, the bulk density was 12 kN/m3 and the relative volume was 1/2. The form of velocity reduction ratio with maximum value was as follows: the flume slope was 12°, the net barrier interval was 18 mm, the bulk density was 17 kN/m3 and the relative volume was 1. The form of bulk density attenuation ratio with maximum value was as follows: the flume slope was 12°, the net barrier interval was 30 mm, the bulk density was 17 kN/m3 and the relative volume was 1/3.