JP2017150263A - Natural ground improvement-type lock bolt reinforcement method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a composite natural ground improvement-type lock bolt reinforcement method that makes work properly executed in such a manner that anchorages in the tip of natural ground and a loose region are set different from each other, by one lock bolt.SOLUTION: In a natural ground improvement-type lock bolt reinforcement method, an expansion-type fabric packer and a pipe for material injection are mounted on the outside of a hollow bolt, and construction work is performed in such a manner that anchorages in the tip of natural ground and a loose region are set different from each other by one lock bolt.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a natural rock improved rock bolt reinforcement method for suppressing extrusion of a tunnel wall surface due to ground pressure in maintenance and management of a railway tunnel.

  Conventionally, a general rock bolt reinforcement method is to drill a hole from a tunnel wall into a natural ground, fill the hole with mortar, insert a lock bolt, and fix the natural ground and the bolt (the following patent document). 1).

  For example, there is no method of fixing a tip with a mortar-based filling material with a single rock bolt and improving a natural ground with a urethane-based injection material at an intermediate portion (loose region of natural ground) (Patent Document 2 below). reference).

  There is an example in which one rock bolt is used to fix the tip with a fast-hardening cement capsule and the middle part with a delayed cement capsule. However, this example is intended to improve the axial force distribution at the time of introducing prestress and is not intended to improve the natural ground (see Non-Patent Document 1 below).

JP-A-7-208097 Japanese Patent No. 3675705

Railway Research Institute: Design guide for countermeasures against deformed tunnels, p93, February 1998

  In general, in a tunnel in which a deformation such as wall extrusion occurs, the ground near the tunnel is relatively healthy, but the ground near the tunnel deteriorates and is loose.

  However, as described above, there is no composite lock bolt reinforcing method in which the tip is fixed with a mortar-based filling material with a single lock bolt and the loosened region is improved with a urethane-based injection material.

  In view of the above-described situation, the present invention provides a composite rock improvement type rock bolt reinforcing method that is appropriately constructed by using a single lock bolt and differently fixing the tip of the natural rock and the loosened area. For the purpose.

In order to achieve the above object, the present invention provides
[1] In the natural ground improvement type rock bolt reinforcement method, an inflatable cloth packer and material injection pipe are attached to the outside of the hollow bolt, and the single rock bolt secures the tip of the natural ground and the loose area. It is characterized by construction with different.

  [2] In the natural rock improvement type rock bolt reinforcing method according to [1], the loosened area is a natural ground improvement effect part in which physical property values are improved by urethane, and the tip part of the natural ground is fixed by an expansion mortar. It is characterized by.

  [3] In the natural rock improvement type rock bolt reinforcement method according to [1] or [2] above, when the tip of the natural ground has a large amount of spring water, a steel pipe expansion lock bolt is used as a fixing effect site for friction. It is fixed by force.

  According to the present invention, the following effects can be achieved.

  It is possible to provide a composite ground improved rock bolt reinforcing method in which a single rock bolt is used for proper construction with different fixation between the tip of the natural ground and the loosened area.

It is a schematic diagram of the 1st natural ground improved type rock bolt reinforcement construction method of this invention. It is explanatory drawing of the 1st natural ground improved rock bolt reinforcement construction method of this invention. It is the sectional view on the AA line of FIG. It is a schematic diagram of the 2nd natural ground improved type rock bolt reinforcement construction method of this invention. It is explanatory drawing of the 2nd natural ground improved rock bolt reinforcement construction method of this invention.

  The natural ground improved type rock bolt reinforcement method of the present invention is such that an inflatable cloth packer and a material injection pipe are attached to the outside of a hollow bolt, and a single rock bolt is used to fix the tip of the natural ground and the loose region. Make the installation different.

  Hereinafter, embodiments of the present invention will be described in detail.

  FIG. 1 is a schematic diagram of the first ground-mount improved rock bolt reinforcing method of the present invention, FIG. 2 is an explanatory view of the first ground-based improved rock bolt reinforcing method of the present invention, and FIG. It is A sectional view.

  In FIG. 1, 1 is a tunnel lining, 2 is a natural ground, A is a loose natural ground, B is a stable natural ground, C is a rock bolt, D is a fixing effect site by expansion mortar, E is a natural ground improvement by urethane It is an effect site.

  2 and 3, 2A is a bore hole made by drilling in advance, 3 is an inflatable cloth bag (packer), 4 is an expanded mortar injection pipe, 5 and 13 are urethane injection pipes, and 6 is an adhesive force. In the case of a high bolt or a low-adhesion bolt and a hollow bolt, in the case of a high-adhesion bolt, urethane is injected after the introduction of pre-stress. This can be done in a lump after the construction of the lock bolt. 7 is a bolt connection sleeve, 8 is an inflatable cloth bag (packer), 9 is a high adhesive force and hollow bolt, and 10 is a mortar leak confirmation hole (flushing hole).

Here, the construction method of the first natural ground improved rock bolt reinforcement method of the present invention will be described.
(1) Drill a natural ground with a boring machine or the like to make a bore hole 2A.
(2) Insert the lock bolt C into the bore hole 2A.
(3) The packer (back) 8 is expanded with mortar pumped by the mortar injection pipe 4.
(4) If mortar is continuously injected as it is, the mortar is filled into the bore hole 2A. Whether or not the mortar has been filled can be confirmed by the mortar being discharged from the mouth through the hole 10 (hole for confirming mortar leak) at the tip of the bolt.
(5) After the mortar is cured (age 1 day), a pull-out test is performed and prestress is introduced.
(6) The packer (hand) 3 is expanded with urethane pumped by the urethane injection pipe 5.
(7) A predetermined amount of urethane is injected by the urethane injection pipe 13 to improve the natural ground.

  FIG. 4 is a schematic diagram of the second ground-mount improved rock bolt reinforcing method of the present invention, and FIGS. 5A and 5B are explanatory diagrams of the second ground-based improved rock bolt reinforcing method of the present invention. It is.

  In these figures, A is a loose ground, F is a ground with a lot of spring water and stable, 21 is a bolt with high or low adhesion, and a hollow bolt. E is a ground with urethane. The improvement (physical property value) effect site, 23 is a steel pipe expansion bolt, and 24 (G) is a fixing effect site by a steel pipe expansion bolt.

  In FIG. 5A, 31 is a water injection pipe, 32 is a bag (packer) made of inflatable mouth cloth, 33 is a bolt connection sleeve, 34 is a steel pipe expansion bolt that expands by water injection, and 35 is a urethane injection pipe (packer expansion). ) And 36 are urethane outlets.

  In FIG. 5 (b), after the water injection pipe 31 is pulled out, urethane is injected into the hollow bolt, whereby urethane is ejected from the urethane ejection port 36, and the loosened region 39 can be improved.

Here, the construction method of the second natural ground improved rock bolt reinforcement method of the present invention will be described.
(1) Make a borehole by drilling a natural ground with a boring machine.
(2) Insert the lock bolt C into the bore hole.
(3) The water injection pipe 31 is inserted into the bolt in order to expand the steel pipe expansion bolt 34 with water pressure.
(4) Water is injected to inflate the steel pipe expansion bolt 34 and fix it to the natural ground. Thereafter, the water injection pipe 31 is pulled out.
(5) Conduct a pull-out test and introduce prestress. In the case of the steel pipe inflatable bolt 34, the fixing force appears immediately after expansion, and therefore no curing period is required.
(6) A bag (packer) 32 made of an inflatable mouth cloth is inflated with urethane fed by a urethane injection pipe 35.
(7) A predetermined amount of urethane is injected. Urethane is ejected from a urethane spout located on the bolt to improve the natural ground.

  In addition, this invention is not limited to the said Example, Based on the meaning of this invention, a various deformation | transformation is possible and these are not excluded from the scope of the present invention.

  The natural ground improved rock bolt reinforcing method according to the present invention is a composite ground improved rock bolt reinforcing method in which a single rock bolt is appropriately constructed with different fixing between the tip and the loose area of the natural ground. Can be used as

DESCRIPTION OF SYMBOLS 1 Tunnel lining 2 Ground mountain A Loose ground mountain B Stable ground mountain C Rock bolt D Fixation effect part by expansion mortar E Natural ground improvement effect part by urethane 2A Bore hole made by pre-drilling 3 Bag (packer)
4 Inflatable mortar injection pipe 5, 13 Urethane injection pipe 6 Bolt with high adhesive force or bolt with low adhesive force 7 Sleeve for bolt connection 8 Inflatable cloth bag (packer)
9 Adhesive force and hollow bolt 10 Mortar leak confirmation hole (flushing hole)
F Stable ground with a lot of spring water 21 Bolts with high or low adhesion 23 Bolts with expanded pipe 24 (G) Fixation effect area with steel pipe with expanded bolt 31 Water injection pipe
32 Mouth Inflatable Cloth Bag (Packer)
33 Bolt connection sleeve 34 Steel pipe expansion bolt that expands by water injection 35 Urethane injection pipe (for packer expansion)
36 Urethane outlet 39 Loose area

Claims (3)

  An inflatable cloth packer and a material injection pipe are attached to the outside of the hollow bolt, and a single rock bolt is used to perform construction with different fixation between the tip of the natural ground and the loose area. Improved rock bolt reinforcement method.   In the natural ground improvement type rock bolt reinforcement construction method according to claim 1, the loosening region is a natural ground improvement effect region in which physical property values are improved by urethane, and the tip of the natural ground is a fixing effect region by expansion mortar. A natural rock improvement type reinforcement method for rock bolts.   In the natural ground improvement type rock bolt reinforcement construction method according to claim 1 or 2, when the tip part of the natural ground has a lot of spring water, fixing by a friction force using a steel pipe expansion type rock bolt at a fixing effect site. A natural rock improvement type reinforcement method for rock bolts.

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