{"id":2497,"date":"2017-02-04T08:00:26","date_gmt":"2017-02-03T23:00:26","guid":{"rendered":"https:\/\/norimen.net\/wordpress\/?p=2497"},"modified":"2026-05-17T11:15:29","modified_gmt":"2026-05-17T02:15:29","slug":"drilling-blockout-angle","status":"publish","type":"post","link":"https:\/\/norimen.net\/en\/drilling-blockout-angle\/","title":{"rendered":"Clearance Angle in Drilling"},"content":{"rendered":"

Hello, everyone.<\/p>\n

This is Enta.<\/p>\n

 <\/p>\n

In rock bolting operations, there are cases where the installation angle is perpendicular to the slope.<\/p>\n

Sometimes the angle of the frame is nearly right angles, or it might even overhang, right?<\/p>\n

\"\"<\/p>\n

This is the kind of situation I'm talking about, lol.<\/p>\n

If the slope contractor and the anchor contractor are different, the slope contractor will install the box-type anchors perpendicular to the slope.<\/p>\n

(*Note: \"Pre-drilling\" refers to the process of drilling holes in advance at the designated locations in void sections or PVC pipes.)<\/span><\/strong><\/p>\n

As is the case on any job site, slope contractors don\u2019t take anchor contractors into account when carrying out their work.<\/p>\n

Not many people realize this, and not many people are thoughtful enough to consider it.<\/p>\n

There wouldn't be a problem if the director had a firm grasp of everything, but,<\/p>\n

The director is busy too, so it's all quite a challenge.<\/p>\n

In that case, the rock bolts would be driven horizontally, and grout would not be injected.<\/p>\n

(It\u2019s not that it won\u2019t fit, but air pockets will form at the top, which can lead to problems with installation and quality.)<\/p>\n

In cases like this, the slope contractor can either ask the supervisor for instructions or take the initiative to adjust the angle, which will resolve the issue.<\/p>\n

 <\/p>\n

As for that angle, it is specified to be at least \u00b15 degrees.<\/p>\n

So, that means the minimum angle is minus 5 degrees.<\/p>\n

However, when a void is inserted at the intersection of the legal boundaries and a 5-degree negative angle is applied,<\/p>\n

When the void comes into contact with the lower rebar, it should be positioned so that it is in close contact with the lower rebar at an angle of at least minus 5 degrees.<\/p>\n

As long as you adjust the angle, there's no problem.<\/p>\n

\"\"<\/p>\n

Public Interest Incorporated Association, Japanese Geotechnical Society, Design and Construction Manual for Soil Reinforcement Methods for Natural Ground, p. 84<\/strong><\/p>\n

However, this is where a problem arises. It\u2019s a problem with root establishment.<\/p>\n

This is the process of planting roots in compacted soil.<\/p>\n

 <\/p>\n

See you later.<\/p>\n

The Secrets of Formwork Removal (2017 Edition) | Collaboration Between Slope Contractors and Anchor Contractors<\/a><\/p><\/blockquote>\n