3.5　Anchor Bolts

3.5.1　Arrangement，types，diameters，properties classification of anchor bolts，quality and dimensions of the parts，number of nuts and threaded length shall comply with the requirements of the equipment concerned.

3.5.2　Anchor bolts for metallurgical equipment are available in two types，namely irremovable bolts and removable bolts，defined as per the possibility of being replaceable during their service lifes.

1　Irremovable bolts（Fig.3.5.2-1），typically including swan-necked type，straight-neckedtype，Ushaped type，straight-rod type and anchor slab type，etc.

Fig.3.5.2-1　Typical types of irremovable bolts

2　Removable bolts（Fig.3.5.2-1），typically including T-head type，screw-in type and oppositescrewing bolts，etc.

Fig.3.5.2-2　Typical types of removable bolts

3.5.3　Depending on specific circumstances，irremovable boltsmay be embedded as follows:

1　One-off embedding method:Before pouring the foundation concrete，fixing brackets or guide plates shall be used to fix the anchor bolts properly first and then the concrete shall be poured to embed the anchor bolts.

2　Pre-openedhole method:When pouring the foundation concrete，appropriate holes shall be preopened where the anchor bolts are to be located，according to the types，sizes and embedment depth of the anchor bolts.For installation of equipment，the anchor bolts shall be placed in the pre-opened holes，and then fine aggregate concrete or grout mix shall be poured into the holesto fix the bolts.

3　Drilling &anchoring method:When the foundation concrete has been completely poured and has obtained adequate strength，holes shall be drilled where anchor bolts are to be located（with diametersand depth determined by the bolt diameters and embedment depth specified in the relevant standards），and then cementing materials shall be poured into the holes.After that，straight-rod bolts shall be inserted into the holes.As long as the concrete is cured as specified in the relevant standards，installation of the equipment may start.

3.5.4　Anchor bolts shall be embedded according to the following constructional dimensions.If the constructional dimensions cannot be achieved，properreinforcing measures shall be taken:

1　The distance between the centerline of the anchor bolts and the edge of the foundations shall be no smaller than 4d（d refers to the bolt diameters），and no smaller than 150mm；For anchor slabbolts，this distance shall be no smaller than the width of the anchor slabs；For removable bolts，this distance shall be no smaller than the width of the fixingslabs.

2　The distance from the anchor bolt bottom to the foundation bottom shall be no smaller than 100mm.

3　The side lengths or diameters of the pre-opened holes shall be determined according to the outline dimensions of the holes and the relevant standards for design of anchor bolts.The distance between the bolt bottom and the holebottom shall be no smaller than 100mm.And the distance from the hole bottom to the foundation bottom shall be no smaller than 100mm.

3.5.5　For anchor bolts with diameters smaller than or equal to 56mm and to be embedded by one-off embedding method，square-or circular-shaped adjustment holes should be provided on the top of the foundations.The adjustment holes should have side length or diameters of 100mm-180mm and depth 200mm-500mm.The distance between the rims of the adjustment holes to the edge of foundations shall be no smaller than 100mm.

3.5.6　Removable bolts without any special requirements should be protected with sealing casings or by filling oiled oakum into the bolt sleeves for 200mm from the top.

3.5.7　For anchor bolts no greater than 56mm in diameter，property grade equivalent to Q235 or Q345，quality grade of C and to be installed by one-off embedding method，the equipment supplier shall specify the property grades in addition to all other requirements in Section 3.1.1 of this Code if the bolts will be fabricated by the equipment foundation constructor.All requirements specified by the equipment supplier shall be completely incorporated into the equipment foundation design documents.The embedment depth of the anchor bolts，if not specified by the equipment supplier，may be calculated as per Appendix D to this Code by using actual bolt forces informed by equipment supplier.For anchor bolts made of Q235 and to be installed by one-off embedding method，if the accurate bolt forcesare not available，the embedment depth can be determined as per Table 3.5.7.

Table 3.5.7　Embedded depth of anchor bolts

Notes:1　Theabove table is applicable to anchor bolts to be installed by one-off embedding method，with foundation concrete strength not less than C20，made of Q235 and other steel with equivalent properties.
2　The minimum embedment depth shall be no smaller than 300mm.
3　If the equipment tends to produce heave loads，or the bolts are exposed to oil erosion and high temperature，the embedment depth should be of a high value；otherwise a low value may apply.

3.5.8　If the equipment elevation needs readjusting due to foundation settlements，the top elevation of anchor bolts may be properly heightened，and the length of the bolts and threads shall be increased accordingly.

3.5.9　For pre-opened holes or adjustment holes for anchor bolts，corrugated steel sheets should be employed to create the holes，and their minimum inner diameters should be compatible to the sizes of the holes.