ANCHOR PRO

User Manual

Version 1.2.0

www.skghoshassociates.com

S. K. Ghosh Associates Inc.

Seismic and Building Code Consulting

334 East Col fax Street , Unit E 43 Vant is Dr ive Palat ine, IL 60067 Al iso Viejo, CA 92656 Ph: (847) 991 -2700 Fax: (847) 991 -2702 Ph: (949) 215-6560 Fax: (847) 991-2702

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DISCLAIMER

Every attempt has been made to ensure correctness in implementing code provisions as well as

the accuracy of the calculations in Anchor Pro. In using the program, however, the user accepts

and understands that no warranty is expressed or implied by S. K. Ghosh Associates Inc.

(SKGA) as to the accuracy or the reliability of the program. The user must carefully read this

manual and thoroughly understand all the inputs parameters and must independently verify the

results. In addition, in no event shall SKGA, or its employees or affiliates be liable for any

indirect, incidental, consequential, or punitive damages whatsoever relating to the use of Anchor

Pro.

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Important Note: In computing the strength of a group of anchors, this program assumes that all the anchors that have been included in the input are in tension when the group is subjected to a tensile load. However, when there is an applied moment on an anchor group, because of an eccentricity or an imposed bending moment, some anchors may develop net compression. User needs to determine if such a condition exists, and if it does, input only those anchors that are in net tension. Similarly, the program assumes that all the anchors that have been included in the input are subjected to shear force in the same direction. If this is not the case (due to a torque), user needs to input only those anchors that carry shear force in the same direction. Thus, it is possible that a user may need to use different subgroups out of the same group of anchors to compute the tensile and shear strengths of the group.

INPUT INTERFACE

Data input in Anchor Pro is done on a single page. The input fields are mostly self-explanatory. However, a short description of each input field is provided below for better clarity. Different input fields are marked by item numbers, as shown below in Figure 1. Item 1: Click on this button to provide some basic information about the project. Information provided here will appear at the top of “Simple Output” and “Detailed Output”. However, this input is only optional and the program will run even without this information. Item 2: Select the version of the MSJC Code you are using. Item 3: Total number of anchors, n. For a group of anchors (n > 1), anchors need to be arranged in a regular rectangular fashion in rows and/or columns. Anchors that are not arranged in a regular rectangular pattern are not addressed by this program. Please read an additional important note above regarding n. Item 4: Number of rows in which the anchors are arranged. This is automatically set as 1 when n = 1. Item 5: Number of columns in which the anchors are arranged. This is automatically set as 1 when n = 1. Item 6: Specified compressive strength of concrete in psi. Item 7: Select anchor type from the drop-down menu – headed or bent (J- or L-) bars. Item 8: Select the grade of anchor steel from 9 built-in options or select “Other” to use a different material. When one of the 9 built-in options is selected, the specified yield strength of steel, fy, is automatically selected by the program, which appears in Item 8. When “Other” option is selected, user needs to specify fy in Item 8.

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Figure 1. Data input page of Anchor Pro

Not all grades of steel are available for all types of anchors. For example, ASTM A 307 Grade C is for hooked bolts only, and not for headed bolts. User should be careful when selecting anchor material for a certain type of anchors.

Item 9: Specified yield strength of anchor steel in psi. Please read the description of Item 7 above for more details. Item 10: Select if the design is ASD or Strength Design using the drop-down menu. Items 11 and 12: Specify the direction of applied shear forces in the X- and Y-Directions here. By default, both options are set to “Automatic”, so that the program assumes that the shear force is directed towards the edge with the smallest edge distance. This is appropriate when the applied shear is caused by seismic activities. However, for non-seismic applications, users can choose if the shear along the X-axis is directed towards the right edge or the left edge, and if the

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shear along the Y-axis is directed towards the top edge or the bottom edge. If there is no shear applied in any direction, leave it at “automatic”. Items 13 through 16: Anchor bolt edge distances, in inches, on all four sides of the anchor or the anchor group. Item 17: Spacing between anchor columns in inches. Columns are assumed to be uniformly spaced. When the number of columns is 1 (Item 5), spacing is automatically set to zero. Item 18: Spacing between anchor rows in inches. Rows are assumed to be uniformly spaced. When the number of rows is 1 (Item 4), spacing is automatically set to zero. Item 19: Specify the thickness of the masonry element where the anchor is attached, in inches. Item 20: Specify nominal anchor diameter, in inches. User can also click on the “Help” button to choose a standard diameter from a drop-down menu (See Item 21 for more detail). Item 21: Specify the effective cross-sectional area of a single anchor, Ab, in square inches. A calculator has been provided to facilitate the computation of Ab. Click on the “Help” button to open the calculator, which appears in a separate window (Figure 2). Effective cross-sectional area is calculated from the following formula:

Ase = π (do – 0.9743/nt)2 / 4

where nt is the number of threads per inch of the anchor. In the calculator, user can type in a diameter (in inches) in the box provided or simply choose from a list of standard diameters from a drop-down menu. When a standard diameter is selected, the value of nt is obtained automatically based on the selected thread type (“Coarse Thread” or “Fine Thread”). However, when the user chooses to enter a custom diameter, the value of nt also needs to be specified.

Figure 2. Calculator for determining Ab

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Once Ab has been calculated, click “OK” to import the values into the corresponding boxes in the main window of the program. User can also input a custom cross-sectional area directly in Item 21. Item 22: If using a bent bar as the anchor, specify projected leg extension, eb, in this box. See the diagram provided in the program interface for the correct way of measuring eb.

Item 23: Specify the effective embedment depth, b, of the anchor(s) in inches. See the diagram

provided in the program interface for the correct way of measuring b in a bent bar anchor. Item 24: Click to calculate the anchor strengths in tension and in shear. Note you will need to have your USB key attached to the computer for strength calculation. A short version of the output will appear in the “Simple Output” window with just the final values in all failure modes. A more detailed description of the strength calculations can be found in “Detailed Output” window.