Revolutionary barrier for rockfall or the like: maintenance-free, highly efficient in dissipating kinetic energy, and fast in installation

Abstract

A safety net system called Pan-barrier is invented to stop rockfall, debris flows, or the like, with three striking advantages: completely maintenance-free, highly efficient in dissipating and diverting kinetic energy, and very fast in installation. The Pan-barrier uses a new type of cable braking—the weight braking—that can be engaged repeatedly without limits or maintenance. The Pan-barrier consists of: 1) a sheet formed by one looped peripheral cable with mesh or net panels attached; 2) two or more anchors holding one side of the sheet close to the ground; and 3) two or more supporting cables (tiebacks), each tied to a ground anchor, erected by a post, and equipped with the weight braking system, holding the top side of the sheet at a designed height, so that the sheet is oblique to the ground. Impact objects are stopped inside the wedge formed between the oblique sheet and the ground.

1 . A safety net system for restraining rockfall, debris flows, or the like by means of a continuous barrier sheet formed by flexible mesh panels, cable nets, ring nets, or the like, wherein for said safety net system said sheet is installed oblique to the ground or slope over which said sheet is suspended, so that: 
 a wedge-shaped or the like shaped space is formed between said sheet and said ground, with one closed side where said sheet and said ground meet; rockfall, debris, or the like goes into said space through the open side(s) of said space;    impacts with debris or the like occur on the underside or facing said ground side of said sheet within said space;    said space stores stopped objects and accumulated debris.    
   
   
       2 . A safety net system according to  claim 1 , wherein said sheet is supported by or attached to a looped frame cable stretched to rectangular shape or the like; the lower side of said frame cable is held down close to said ground by means of anchors or the like while the opposite side or the top side of said frame cable is held up by means of posts, tiebacks, supporting cables, or the like.  
   
   
       3 . A safety net system according to  claim 2 , wherein said tiebacks are erected or supported by posts, natural topographic highs, or the like and hold up said top side of said frame cable.  
   
   
       4 . A safety net system according to  claim 2 , wherein a mesh screen or the like drape is draped from said top side of said frame cable.  
   
   
       5 . A safety net system according to  claim 2 , wherein all the connections to said frame cable permit sliding.  
   
   
       6 . A safety net system according to  claim 1 , wherein objects, usually heavy, are attached to or are hung from supporting cables of said sheet for tensioning and braking of said sheet in case of impacts.  
   
   
       7 . A weight tensioning and braking system for safety nets, impact fences, or the like, wherein said weight tensioning and braking system comprises one or more weights, such as metals, concretes, logs, rocks, or the like, attached or fixed to supporting or tieback cables of impact fences or the like to create sagging of said supporting or tieback cables for the purpose of tensioning or braking, or both.  
   
   
       8 . A weight tensioning and braking system according to  claim 7 , wherein said supporting or tieback cables are supported by erecting devices like posts and are connected to said weights and flexible barrier sheet(s) at different or opposing sides of said erecting devices;  
   
   
       9 . A weight tensioning and braking system according to  claim 8 , wherein said weights are connected to said supporting or tieback cables by means of strings of different lengths, said strings range from zero length (said weights fixed on said supporting or tieback cables directly) to lengths that allow said weights lying on ground.