The anchor bolt edge distance, lbe, is measured in the direction of the applied load from the center of the anchor bolt to the edge of the masonry. When the projected areas of adjacent anchor bolts overlap, the portion of the overlapping area is reduced by onehalf for calculating a pt or a pv as shown in figure 3. Design software whether modeling anchors or modular supports, maintaining firestop systems, or managing assets, our modeling and bimtofield software enables faster time to value for your structural, energy and industry, and firestop projects. Design of anchor bolts in masonry article pdf available in progress in structural engineering and materials 84. Design so that anchor strength is governed by steel tensile or shear yielding. Guide on design of postinstalled anchor bolt systems in hong. Failure mechanism for largesized grouted anchor bolt under. Behavior and design of single, headed and unheaded, grouted anchors under tensile load authors. For such columns, the simple columnbaseplate connection detail shown in figure 1. The anchor bolt edge distance, l be, is measured in the direction of the applied load from the center of the anchor bolt to the edge of the masonry. The design strength of grout should be the same as for concrete of equivalent. Post placed anchor bolts are inserted in the drilled hole and grouted tightly into place.
After the core is removed, the diameter of the cored hole shall be determined in the field and a replacement anchor shall be sized so that no more than 18 of annular space shall exist between the new threaded studanchor bolt and the side of the cored hole wall. Final deficiency rept re grouted anchor bolts on main steam. Failure mechanism for largesized grouted anchor bolt. This figure is basedon resultsof anchor tests in rockscommonlyfoundon wrangell island, southeastalaska, andshould be usedwith care at other localitieswhere extensiveweathering, fracturing,and discontinuousrock unitsare encountered anchor selection and design criteria. One change was to increase the calculated shear crushing strength by 67%.
This document provides detailed information on design analyses for ground anchored systems. The wedge shaped design on the bottom of the bolt transfers the tensile load of the stud into a. Anchor bolts subjected to combined axial tension and shear must also satisfy the following unity equation. Prior to anchor placement in the grouted hole, all material which might interfere with bond between the anchor and the grout shall have been removed.
Anchor selector size hole cleaning option1 head type base material corrosion resistance features approvals. When the projected areas of figure 2minimum effective embedment lengths bentbar anchor bolt headed anchor bolt grout minimum clearance between anchor and nearest masonry surface. Anchor bolt pull out strength is the force required to pull a single bolt out of its foundation. Oct 12, 2017 strength design was added to the tms 402 building code for masonry structures in 2002.
Grout is injected into the grout sock through the grout tube at approximately 2. Design guide 1, 2nd edition base plate and anchor rod design mentary to the aisc seismic provisions notes some signi. Parameters considered in this study included various ratios of embedment depth to bolt diameter, different grout properties, and two concrete failure theories. A template is a good idea for positioning the drill holes and again a good idea to align the bolts hanging in those same holes. Testing structural details 9 failure mode allowable stress 8. Civil and coastal engineering based on experimental test results, a set of design equations were developed for. Guide on design of postinstalled anchor bolt systems in. Guide for design and installation of anchor bolts used in. Pdf design of anchor bolts in masonry researchgate. Guide for design and installation of anchor bolts used in transportation structures parsons 11 brinckerhoff 1. Behavior and design of grouted anchors loaded in tension including edge and group effects and qualification of engineered grout products by jennifer lynn burtz august 2003 chair.
Michigan department of transportation mdot mechanical. Guessing is concerning bolt diameter and bolt length is a poor practice. Anchor strength and long term performance are dependent on a variety of factors. C5a is based on the capacity of the anchor bolt in a properly designed concrete or masonry foundation system. However, most masonry is still designed by the allowable stress design method. Final deficiency rept re grouted anchor bolts on main. Example a1 single stud, tension only example a2 single stud, shear only example a3 single stud, combined tension and shear example a4 anchor bolt, combined tension and shear example a5 single rebar, combined tension and shear. The anchorage may be of any type that is lot wedge type, expansion shell type, etc. Cementitious grouted anchors mechanical anchors that are installed in a large diameter preformed or drilled hole. Guide for design and installation of anchor bolts used in transportation structures parsons 24 brinckerhoff castinplace embedded anchors anchors that are positioned before the concrete is cast.
Anchor bolts will be installed per this specification. It is to be emphasised that failure of the bolt needs to be the objective of the designer. Holes shall be surface dry and shall have had all foreign and loose material removed immediately prior to grout placement. The anchor and external plug are then inserted into the hole and tightened in the same manner as the dropin anchor with an external plug. The behavior of anchor bolts under combined loading is not well understood, leading to current design procedures that incorporate a conservative linear interaction relationship. Anchor bolt in concrete as a comparison, an anchor bolt set in a concrete foundation will typically crack up and out from the bottom of. D bolt diameter in inches l length in inches of the bolt embedded in grout does not include the portion of the bolt that is wrapped with tape or inside a bolt sleeve. Attachment a to this specification specifies the type of hilti anchor to use for each anchor location. As for proposed design procedures for grouted anchors, good references would include an article by zamora, cook, konz, and consolazio3 and a report by cook and burzt. Horizontal shear capacity for a specific spacing of anchor bolts is based on bearing of the anchor bolt against concrete or grout. Thirtytwo, largescale pullout tests of connectors grouted in galvanized steel and plastic ducts were conducted to investigate the response of this type of connector. Long anchor rods embedded in concrete will strain much more than highstrength bolts or welds in beamtocolumn connections. Any portion of the projected area that falls within an open cell, open core.
Practical design and detailing of steel column base plates. Pdf grouted anchors are often used to connect steel structures and microwave towers to concrete. The final type of mechanical expansion anchor is the selfdrilling anchor refer to figure 3. The selfdrilling anchor attaches to a rotohammer, which is used to drill the proper size hole. Anchor bolt data anchor bolt material f1554 grade 36 f1554 grade 55 f1554 grade 105 a307 grade a a307 grade c a36 a193 grade b7 dia 2. Topics discussed include selection of design earth pressures, ground anchor design, design of. Headed anchor rods, 7576 headed grouted anchors, 99, 99f headed stud anchors, 75 headed studs, 15. For polymer grouted anchor bolts, the load capacity of. Strength design generally results in more efficient designs than with allowable stress design. Rockbolts generally consist of plain steel rods with a mechanical or chemical anchor. The sock acts as a temporary shutter whist it expands to tightly fit the contours of the core hole and local voids and fissures. Tests of grouted anchor bolts in tension and shear authors. Rockbolts and cables introduction rockbolts and dowels have been used for many years for the support of underground excavations and a wide variety of bolt and dowel types have been developed to meet different needs which arise in mining and civil engineering. Hdr25 shipping assembly complete with an ar6525 coneshell anchor hdr site assembly.
The grouted sock anchor, supplied to the specified length, is inserted into a predrilled core hole. It can effectively restrain the deformation and displacement of roadway surrounding rock, and improve the supporting rigidity and shear strength of bolt support system. The behaviour of grouted anchors was expected to be similar to either castinplace headed anchors or postinstalled adhesive anchors depending on the anchor configuration. This paper combines the concrete capacity design model and the uniform bond stress model into a rational procedure for grouted fastener strength design. A wide variety of anchor bolt grout options are available to you, such as double components adhesives, other adhesives. To simulate such a structural behavior and failure mode of grouted anchor bolt. Column base plates are bearing on grout and concrete. There were two major changes to the anchor bolt design provisions in the 2016 edition of tms 402. Interestingly, grouted fastener test data showed that the performance of grouted anchors rivals that of castinplace fasteners. The term anchor below includes both bolts and reinforcing bars. The anchor and external plug are then inserted into the hole and tightened. Practical design and detailing of steel column base plates table of contents description page no. The fully grouted bolts technology can effectively inhibit the separation and sliding of rocks, and strengthen the integrity of rock mass within the anchorage range. Anchor bolt design guide example 3 shear lug plate section design design a shear lug plate for a 14in.
Since grouted anchors are requiredto transfer loads the same as castinplace anchors, the appropriate design and. Rock bolts are used as the main support for structures such as tunnels and mines where safety is critical. Strength design was added to the tms 402 building code for masonry structures in 2002. Typically, a structural engineer evaluates several factors before proceeding with an anchor bolt grout project. This paper combines the concrete capacity design model and the uniform bond.
Fastening systems in the form of anchor bolts are usually. The base plate and shear lug have f ya 36 ksi and f c 3 ksi. Guide on design of postinstalled anchor bolt systems in hong kong. Anchor bolt or anchor stud design using aci 31811 or aci. Behavior and design of single, headed and unheaded. The other change was to go from a linear interaction equation for combined bending and shear to an elliptical interaction equation. Connectors in precast bent cap systems francisco j. However, practical limitations on the embedment depth may sometimes prevent full development of the bolt steel strength. The objective of this research was to investigate the interaction behavior of anchor bolts in grouted concrete masonry under combined tension and shear loading. Final deficiency rept re grouted anchor bolts on main steam line supports. To order a complete tek manual or tek index, contact ncma publications 703 71900. Strength design of anchor bolts pt the design provisions for anchor bolts using the. The primary grout body in the bond length of the anchor is fractured by introducing additional grout through a post grout line with pressures up to 1200psi 8mpa.
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