| Passive protection systems are currently the mainstream protection methods for intercepting and preventing dangerous rock falls.Passive protection systems have been widely promoted in the road and railway industry for their advantages such as fast installation,low engineering costs,and high protection energy levels.Differ to passive protection systems,Guided rock fall flexible protection system is a lightweight protection method.Guided rock fall protection system is restricted during the movement of rocks to achieve the purpose of guiding the rocks to the designated accumulation area at a low speed.At present,the research on the guided falling rock protection system is relatively lacking,and its layout pattern changes in different slopes need to be further studied.Therefore,this research takes the dangerous rock fall of rock slope as the research object,and analyzes the layout modes of passive protection system and guided rock fall protection system in different slope configurations.The main research results are:(1)Taking the most common compound slopes of highways and railways as prototypes,and taking stone walls as examples to analyze the three factors that affect the layout mode of the passive protection system,the horizontal distance of the passive protection system from the base of the slope,the height of the passive protection system and the inclination angle,studying the follow-up changes between the various factors of the passive protection system.On this basis,the impact of horizontal distance,height and inclination of passive protection system on rockfall protection in slopes of different heights is studied,and recommendations are made to select layout schemes for different slope heights.(2)Using the ANSYS LS-DYNA numerical analysis software to study the three-stage energy consumption mechanism of the guided falling rock protection system.Carrying out the parameter analysis of each rockfall parameter affecting the protection ability of the guided rockfall protection system,and obtaining the follow-up relationship between the rockfall volume,rockfall quality,rockfall incidence rate and the rockfall escape rate,to provide design guidance for the selection of guided rockfall protection system in linear slope.(3)Taking the inflection point of the slope as the distinguishing point,the complex slope configuration is disassembled into a convex slope and a concave slope.In order to study on the influence of the layout mode of guided rockfall protection system on rockfall protection,selecting the modes of laying the protective net only on the uphill section,only on the downhill section,and on the whole slope section individually based on the three parts of the initial falling position of the falling rock,the subsequent movement position of the falling rock,and the whole process of the falling rock.Evaluating the layout of the guided rockfall protection system in complex slopes,and studying the efficient and economical layout scheme of the guided rockfall protection system in complex slopes.(4)Discussing the special slope shape existing in the dismantling slope configuration.Aiming at the problem that it is difficult to prevent and control dangerous rocks through a single guided rockfall protection system in a special slope shape,the protection effect of multiple combined structure layout modes in a special slope shape is studied.In addition,in order to further improve the protection capability of the guided rockfall protection system and limit the bounce height of the rockfall at the inflection point of the slope,several energy dissipation parts suitable for the guided rockfall protection system are proposed.At last,discussing the research direction of the guided rockfall protection system under the impact of high kinetic energy rockfall. |
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