Rock bolting has firmly used as the coal mine roof reinforcement in underground coal mine. The bolting effect of fully grouted rebar bolt is closely related to the bolt surface profile. This paper provides an experimental study to confirm that bolt rib internal length has great influence on bolting effect. Pull-out tests were conducted using rebar bolt with different rib spacings of 12, 24, 36 ...

By Timothy Phillips Vaughan, MS. Washington State University May 2010 Chair: David I. McLean This research evaluated the structural performance of reinforced masonry shear walls conforming to requirements given in the 2008 MSJC Building Code Requirements for Masonry Structures under cyclic lateral loading. Seismic design provisions in the 2008 MSJC provide prescriptive requirements for three di...

Ground-source heat pump (GSHP) utilizes the immense renewable storage capacity of the ground as a heat source or sink to provide space heating, cooling, and domestic hot water. GSHP systems are generally comprised of water source heat pumps and ground heat exchangers (GHX). Vertical closed-loop GHX is used predominantly in commercial and institutional applications. Closed loop GHX consists of a...

Trusses used for roof support in coal mines are constructed of two grouted bolts installed at opposing forty-five degree angles into the roof and a cross member that ties the angled bolts together. The load on the cross member is vertical, which is transverse to the longitudinal axis, and therefore the cross member is loaded in the weakest direction. Laboratory tests were conducted to determine...

Split-set bolt is widely used in supporting stope and roadway surrounding rock metal mines. The maximum pull-out force generated by the relative slippage between anchor drill hole can serve as an indicator for assessing its anchoring force, of grouted exhibits certain regularity over time. This test was carried out at different time points after construction split-set using drawing equipment, v...

The grouted mortise-tenon joint, invented as the connection between large prefabricated elements, is most important component in underground structures. This paper conducts analysis of load-carrying capacity performance and failure mode with 1 : prototype test key working direction different double joint types for metro station. resistance moment developed used to analyze bending bearing charac...

A dynamic numerical method is established to simulate the stability of surrounding rocks retained roadway in FLAC3D, along with a double-yield constitutive model re-compaction process gangue and strain-softening characteristic coal grouted fragmented after yielding. The simulation reveals that grouting slurry diffusion range, mining affecting stage behind working face rib deformation are closel...

This paper proposes a new interface constitutive model for fully grouted rock-bolts and cable-bolts based on pull-out test results. A database was created combining published experimental data with in-house tests. By means of comprehensive framework, Coulomb-type failure criterion accounting friction mobilization defined. During the elastic phase, in which joint is not yet created, proposed pro...