Split Set/Swellex
Split Set and Swellex bolt types allow you to model a fully bonded, frictional bolt type.
Split Set and Swellex are presented as two different bolt types in RocTunnel3
for modelling convenience. However, the two bolt types are implemented
in exactly the same way in the RocTunnel3 analysis. The only difference
between the two selections is that the default Bond Strength is higher for Swellex than for Split Set. This value can of course be changed by the user.
Furthermore, the implementation of the Swellex/Split Set models in RocTunnel3 is essentially the same as the Grouted Dowel model, with the condition that the Bonded Length
for a Swellex/Split Set is always 100%. Except for this difference, the
implementation of the Swellex/Split Set and Grouted Dowel models are
the same. For details, please see the Grouted Dowel topic.
General
Force Application and Orientation
- Force Application: Active or Passive
- Use Bolt Orientation Efficiency (optional): Cosine Tension/Shear or Linear Tension/Shear
Tensile
- Tensile Capacity
Shear and Compression
- Use Shear Capacity (optional): Shear Capacity
- Use Compression Capacity (optional): Compression Capacity
Pullout and Stripping
Plate Capacity
- Plate Capacity
Bond Strength
- Bond Strength
- Material Dependent (optional): sum of bond strength of material x bolt length passing through material specified, otherwise the global Bond Strength is used
Bolt Force Diagram
A Bolt Force Diagram for a Swellex bolt, which
exhibits all three failure modes, is shown below. If the Plate Capacity
is less than the Tensile Capacity, then "stripping" is a possible
failure mode. If the bond capacity at either end is sufficient to equal
the tensile capacity of the bolt, then tensile failure can occur along
the middle of the bolt, as shown in the following figure.
Force diagrams for Swellex or Split Set bolts with no faceplate, are shown below (if Plate Capacity = 0, the origin of the force diagram is at zero force). For the Swellex example, tensile failure is possible due to the relatively high bond strength of Swellex bolts. For the Split Set example, tensile failure cannot occur, because the bond capacity is not sufficient to equal the tensile capacity of the bolt. Therefore only stripping or pullout can occur. Actual force diagrams will depend on bolt length, bond strength, tensile capacity and plate capacity.
