JPS60184200A - Anchoring of lock bolt anchor - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for anchoring rock bolts, anchors, etc. to earth having a low deformation coefficient.

Conventionally, when applying the NATMT method, it has been known to reinforce the ground by driving rock bolts into other mountains. This method involves inserting a rock bolt, anchor, etc. into a hole drilled in another mountain, and fixing it in the hole using a filler or a filler mixed with an expanding material.

Conventionally, the following filling materials have been used:

(1) A mixture of ordinary Portland cement, sand and water.

(21(1) mixed with rapidly hardening materials such as calcium aluminate and gypsum.

(3) Also, the above materials +11. (For example, 21 with a setting modifier added. These materials had the effect of increasing the bonding strength between the filler and the rock in hard rock mountains, but they do not work well in rocks with a low deformation coefficient. It had no effect.

The present invention provides a method for fixing rock bolts, anchors, etc., which can increase the strength of the ground in a ground with a low modulus of deformation (low Young's modulus) as described above, and the bond strength between the filler and the ground. The gist is that a turgor-generating material that generates turgor pressure is added and mixed with a cement-based filling material, and the slurry of this mixture or the water absorption of this mixture is used to drill holes in other mountains with a low deformation coefficient. A method for fixing a rock bolt, anchor, etc., which is inserted into a borehole and is fixed by the compression and tightening action of a turgor-generating material.

The method of the present invention is targeted at sandy mountains with low deformation coefficients and soft and hard rocks with low deformation coefficients.

The turgor pressure generating material used in the present invention is suitably one that generates turgor pressure upon hydration, and a slow crushing agent used for rock crushing etc. is used. For example, “Calmite (Nippon Cement Co., Ltd.),” “Plystar (Onoda Cement Co., Ltd.),” “S
- Might (Sumitomo Cement Co., Ltd.) J.

These include "Reomite (Osaka Cement Co., Ltd.)" and "Denka Chemiasox (Denki Kagaku Kogyo Co., Ltd.)."

Further, as the cement I-based filling material, a filling material containing Portland cement as a main component, such as cement mortar, is used.

The above-mentioned turgor pressure generating material is, for example, 100 parts by weight of cement.

It is used by adding 5 to 50 parts by weight to 50 to 100 parts by weight of sand. Before use, add water to this mixture.
/C=0.3 to 0.7 and after stirring, the mixture is injected into a hole in the ground that has been drilled in advance. Thereafter, a lock bolt, anchor, etc. is inserted into the hole.

In addition, the above mixture is filled in an air-permeable and water-permeable container, and when used, it is immersed in water to absorb enough water, and then loaded into the hole, and then used for rock bolts, anchors, etc. may be inserted into the hole.

The mixture filled in the above manner hydrates and hardens within the pores and generates turgor pressure. The transmission of stress in the ground due to this turgor pressure makes the ground tighter and increases its strength, and also increases the bonding strength between the filler and other mountains, improving the pull-out strength of rock bolts, anchors, etc.

In this case, in order to prevent the destruction of the ground, it is necessary to set the turgor pressure in accordance with the deformation coefficient of the ground.

According to the present invention, a rock having a low deformation coefficient is compressed and compacted by turgor pressure, and °C1[1! Since the board is improved, it becomes possible to improve the financial ability to pull out rock bolts, anchors, etc. from the ground with a low deformation coefficient, which was previously impossible, and it is possible to perform safe and reliable construction using the NATM construction method.

Examples 1-4. Comparative Examples 1 to 3 ■) Materials used Water turgor pressure generating material; A Commercial product "Calmite" (Rohon Cement Co., Ltd.) 2) Modulus of deformation of other threads (Young's modulus) 1350.420°1050 kg/crA 3) Hole Size: Straight ￥42 fin x depth 2mD = 25m
m, 1 = 2 m, unusual shape.

When the present invention was applied to the above-mentioned rock according to the above specifications,
I got the following results.

Claims (1)

[Claims] (11) A turgor-generating material that generates turgor pressure is added and mixed with a cement-based filling material, and the slurry of this mixture or the water absorption of this mixture is poured into a borehole in a ground having a low deformation coefficient. A method for fixing rock bolts, anchors, etc., which is characterized by fixing the rock bolts, anchors, etc. inserted into the borehole by compressing and tightening the turgor-generating material after loading. (2) The above-mentioned low deformation coefficient. A rock having a Young's modulus of 300
The method for fixing rock bolts, anchors, etc. according to claim 1, wherein the rock bolt is a rock mass of ~1000 kg/cJ. (3) The rock bolt according to claim 1, wherein the turgor pressure is 10 kg/cf or more, and the amount of the turgor-generating material is selected in accordance with the deformation coefficient of the ground. How to fix anchors, etc. (4) The method for fixing rock bolts, anchors, etc. as set forth in claim 1, wherein the cement-based filling material comprises Portland cement, sand, and water.