Ram pressure equation cgs11/25/2022 No, Ram Concept designs stud rails (including the Ancon Shear fix) but not a traditional shear cage. Can Ram Concept design a standard reinforcement cage to prevent a punching failure? So Concept reports ( phi V c / b o d ) as the allowable stress. V c = ( a s * d / b o + 2 ) (root f'c) b o d Yes, for example, the ACI equation 11-34 indicates: When Concept reports the punching shear allowable stress, is it already reduced by phi? This approximation is used so that the program can handle critical sections with irregular shapes. The critical section for circular columns is approximated as an equivalent polygon with 16 sides and the properties are calculated using the resulting linear segments. How does Ram Concept calculate the critical section properties for circular columns? For cases where a tendon is anchored within the column shape and vertically eccentric to the mid-depth of the punching shear failure plane, this can also result in a significant moment in the punching shear reactions. Remember, the punching shear resultants are acting through the centroid of the failure plane, not through the column centroid, so moments due to eccentricity are common for edge or corner conditions even where the column is pinned.Īdditionally, when post-tensioning is provided and the Calc Option to "Include tendon component in punch check reaction" is checked, then the tendons are converted into equivalent concentrated balance loads and RAM Concept will modify (normally reduce) the punching reaction by any concentrated forces located within the column shape. Surface loads around the column within the punching failure plane are not discounted from the demand. In brief, the program uses the column reactions, less any point loads or column above reactions inside the column shape. Refer to the program manual, section "How does RAM Concept handle punching shear?" and "Step 1: Determine the force envelopes to be checked" for details. How does Ram Concept calculate the demand for punching shear calculations? For this reason we do not recommend checking punching for column pilasters at wall locations. Punching around walls is also not considered. No, in Ram Concept each column reaction is used in an independent punching check, No group punching for close columns is considered. Can Ram Concept check punching shear for a pair or group of columns? If the shear demand exceeds this maximum strength, then no stud rails will be designed. #RAM PRESSURE EQUATION CGS CODE#The ACI code limits the shear strength, Vn, of the slab. If the rails are extended to this point and the design is not satisfied, then no stud rails will be designed by the program. Stud rails are extended to the extents of the search radius of the punching shear check. Why does the Punching Shear Check fail even when the box for "Design SSR if Necessary" is checked? In some cases, reducing the punching check radius so that the circle does not cross 2 opposite slab edges is a solution. As such it's not a valid punching check, though one-way shear should certainly be checked using a design strip or design section. This error occurs when there is a potential failure plane that is a single line (in plan). Why do I get an error "Punching Critical Section has Ix (or Iy) = 0 at."? This can happen if the column is moved and the model remeshed after the punching checks were initially placed. "No Calc" is also displayed where the punching shear check is misplaced. In cases where "No cutoff critical sections are found", the Punching Shear Stress plots will indicate " No Calc". This warning is more likely when the search radius is so small that the critical section a distance "d" from the face of the support is bound to be beyond the search radius. The warning message "No column critical sections were found at a punch check" or "No cutoff critical sections found" can also occur under the same conditions. Modifying the punching check by reducing the Search Radius or changing the Edge Treatment could potentially help as well. #RAM PRESSURE EQUATION CGS FULL#For edge columns, the concrete beams or slabs should typically cover the full column area. In cases where a punching shear check really is required, try simplifying the geometry to limit the number of changes in thickness at the column. If that's the case simply delete the offending punching shear check to proceed. Often in those cases no punching shear check is required, provided the beams have sufficient one way shear capacity in both directions. The error usually occurs where multiple beams of varying thickness intersect the column creating an overly complex punching shear failure plane. The location in the error message is the location of a column and punching shear check in the model. Why do I get an error about "Too many slab shapes intersecting the column shape"?
0 Comments
Leave a Reply.AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |