1、翻译部分Effect of grout properties on the pull-out load capacity of fully grouted rock boltA. Klc, E. Yasar*, A.G. CelikAbstractThis paper represents the result of a project conducted with developing a safe, practical and economical support system for engineering workings. In rock engineering, untension
2、ed, fully cement-grouted rock bolts have been used for many years. However, there is only limited information about the action and the pull-out load capacity of rock bolts, and the relationship between boltgrout or groutrock and the influence of the grout properties on the pull-out load capacity of
3、a rock bolt. The effect of grout properties on the ultimate bolt load capacity in a pull-out test has been investigated in order to evaluate the support effect of rock bolts. Approximately 80 laboratory rock bolt pull-out tests in basalt blocks have been carried out in order to explain and develop t
4、he relations between the grouting materials and untensioned, fully grouted rock bolts. The effects of the mechanical properties of grouting materials on the pull-out load capacity of a fully grouted bolt have been qualified and a number of empirical formulae have been developed for the calculating o
5、f the pull-out load capacity of the fully cement-grouted bolts on the basis of the shear strength, the uniaxial compressive strength of the grouting material, the bolt length, the bolt diameter, the bonding area and the curing time of the grouting material.Keywords: Rock bolt; Grouting materials; Bo
6、lt pull-out load capacity; Bolt geometry; Mortar1. IntroductionIn rock engineering, rock bolts have been used to stabilise openings for many years. The rock bolting system may improve the competence of disturbed rock masses by preventing joint movements, forcing the rock mass to support itself (Kais
7、er et al., 1992). The support effect of rock bolt has been discussed by many researchers(e.g. Hyett et al., 1992; Ito et al., 2001; Reichert et al., 1991 and Stillborg, 1984). Rock bolt binds together a laminated, discontinued, fractured and jointed rock mass. Rock bolting not only strengthens or st
8、abilizes a jointed rock mass, but also has a marked effect on the rock mass stiffness (Chappell, 1989). Rock bolts perform their task by one or a combination of several mechanisms. Bolts often act to increase the stress and the frictional strength across joints, encouraging loose blocks or thinly st
9、ratified beds to bind together and act as a composite beam (Franklin and Dusseault, 1989). Rock bolts reinforce rock through a friction effect, through a suspension effect, or a combination of two. For this reason, rock bolt technique is acceptable for strengthening of mine roadway and tunnelling in
10、 all type of rock ( Panek and McCormick, 1973).Generally rock bolts can be used to increase the support of low forces due to the diameter and the strength of the bolt materials. They enable high anchoring velocity to be used at closer spacing between bolts.Their design provides either mechanical cla
11、mping or cement grouting against the rock (Aldorfand Exner,1986).Anchorage system of rock bolt is normally made of solid or tube formed steel installed untensioned or tensioned in the rock mass (Stillborg, 1986). Rock bolts can be divided into three main groups according to their anchorage systems (
12、Franklin and Dusseault, 1989;Aldorfand Exner, 1986; Hoek and Wood, 1989; Cybulski and Mazzoni, 1989). First group is the mechanically anchored rock bolts that can be divided into two groups: slit and wedge type rock bolt, expansion shell anchor. They can be fixed in the anchoring part either by a we
13、dge-shaped clamping part or by a threaded clamping part. Second group is the friction-anchored rock bolts that can be simply divided into two groups: split-set and swellex. Friction-anchored rock bolts stabilise the rock mass by friction of the outer covering of bolt against the drill hole side. The
14、 last group is the fully grouted rock bolts that can also be divided into two groups: cement-grouted rock bolts, resin grouted rock bolts.A grouted rock bolt (dowel) is a fully grouted rock bolt without mechanical anchor, usually consisting of a ribbed reinforcing bar, installed in a drill hole and
15、bonded to the rock over its full length (Franklin and Dusseault, 1989). Special attention should be paid to cement-grouted bolts and bolts bonded (glued, resined) by synthetics resins for bolt adjustment. Grouted bolts fix the using of the coherence of the sealing cement with the bolt rod and the ro
16、ck for fastening the bolts. Synthetic resin (resined bolt) and cement mortar (reinforced-concrete bolt) can be used for this type rock bolt. These bolts may be anchored in all type of rock. Anchoring rods may be manufactured of several materials such as ribbed steel rods, smooth steel bars, cable bolts and other special finish (Aldorfand Exner, 1986).Grouted bolts are widely used in mining for the stabilisation of tunnelling, mining roadway, drifts and shafts for
