1. A system for controlling packet forwarding through a point-to-point (p2p) connection between first and second end nodes of a packet network domain having a mesh topology, the system comprising:
a sub-ring network instantiated in the network domain, the sub-ring network comprising a pair of topologically diverse ring spans extending between the first and second end nodes;
wherein each of the end nodes is controlled to forward packets of the p2p connection through the sub-ring network in accordance with a ring network routing scheme, and an intermediate node traversed by one of the ring spans is controlled to forward packets of the p2p connection through the ring span in accordance with a linear path routing scheme.
2. The system as claimed in claim I, wherein at least one of the end-nodes is designated as a Ring Protection Link Owner, and is controlled to impose a channel block to prevent forwarding of traffic of the sub-ring network through a selected one of the ring spans.
3. The system as claimed in claim 1, wherein the network domain is any one of an Ethernet domain, an IP domain, a Provider Backbone Transport (PBT) domain, a Multi-Protocol Label Switching (MPLS) domain, and a Virtual Private LAN Service (VPLS) domain.
4. The system as claimed in claim 2, wherein one span of the sub-ring network is designated as a Ring Protection Span, and wherein respective channel blocks are imposed at opposite ends of the Ring Protection Span.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
What is claimed is:
1. A method for reinforcing a slope using a reverse analysis technique comprising the steps:
studying a underground water level, slope configuration, a soil condition status and rock joint orientation in connection with an applicable limit of the slope, on the basis of which determining soil parameters including a cohesion and an internal friction angle using the Janbu method are determined so as to be adapted to characteristics of the deformed ground;
analyzing stability of the slope using the soil parameters by the Janbu method to estimate a driving force and a resistance force of the slope;
planning a construction section of a reinforcement zone to be constructed with reinforcement members in order to increase the resistance force of the slope;
determining a position and a quantity of subterranean horizontal drain holes in consideration of the underground water level condition to study an external stability;
checking an internal stability within the reinforcement zone against a critical failure section in consideration of a pull-out force and a shear capacity of the reinforcement member; and
preparing design drawings so as to satisfy the external and internal stabilities and carrying out a reinforcement construction work.
2. A method according to claim 1, wherein an apparent cohesion increasing with construction spacing between the reinforcement members is preferably
48
C
=
3.6
_
~
4.2
_
when a SD40:25MM reinforcing steel bar is used,
49
C
=
4.9
_
~
5.6
_
when a SD40:29MM reinforcing steel bar is used,
50
C
=
5.9
_
~
7.5
_
(
t
m
2
)
when a SD40:32MM reinforcing steel bar is used as a nail bar.
3. A method according to claim 1, wherein the step of carrying out the reinforcement construction work comprises the steps of: insert-laying the reinforcement members in the slope in accordance with the design drawings; mixing cement, water and high fluidizing agent with each other to produce grout and gravitationally injecting the grout around the reinforcement members; laying slope drain holes in the slope in such a manner that they, extends beyond the reinforcement zone in accordance with the design drawings; installing main earth-pressing steel plates, PVC-coated wire mesh and sub earth-pressing steel plates to fix the reinforcement members; and treating surfaces of the slope with general artificial soil covering or artificial soil covering mixed with natural monofilaments by a spray vegetation attaching method.
4. A method according to claim 1, wherein a safety factor of the slope is 1.4 or more in the construction section of the reinforcement zone.
5. A method according to claim 1, in the case of a weathered residual soil layer slope or a rock mass slope having remarkable joint orientation, the step of determining the soil parameters may be performed by determining a dip angle (a bedding plane angle or a plunge angle) () of the slope joint as the internal friction angle () and inversely calculating a cohesion (C) at the determined internal friction angle under a condition for limit equilibrium state Fs1.0.
6. A method according to claim 1, in the case of an unsaturated earth cut slope ground, the step of determining the soil parameters may be performed by determining the internal friction angle () through a direct shear test and inversely calculating the cohesion (C) at the constant internal friction angle (const.) under a condition for limit equilibrium state Fs1.0.
7. A method according to claim 1, in the case of degradation or deformation of the slope, the step of determining the soil parameters may be performed by determining the internal friction angle () through the direct shear test and inversely calculating the cohesion ( C ) considering an estimated failure line under a condition for limit equilibrium state 0.85F,1.03.
8. A method according to claim 1, in the case that the slope is unstable and forms an irregular stratified profile corresponding to a limit equilibrium state, the step of determining the soil parameters may be performed preliminarily by assuming that a critical failure line passes through the lowest portion of an upper stratum of the slope, determining the internal friction angle (r) through the direct shear test for a specimen of the upper stratum of the slope and inversely calculating the cohesion ( C ) under a condition for limit equilibrium state 0.9F,1.05, and secondarily by assuming that the critical failure line passes through the lowest portion of a lower stratum of the slope, determining the internal friction angle (r) through the direct shear test for a specimen of the lower stratum of the slope and inversely calculating the cohesion ( C ) under a condition for limit equilibrium state 0.9F,1.05.