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  • The work consists of drilling grout holes, exploratory holes, and check holes, pressure testing, pressure washing, and injecting suspension grout under pressure includes furnishing of all materials, labor and equipment as described and specified.   

    MS Plat with chemical anchor fixing work

    Column base plate connections are the critical interface between the steel structure and the foundation. These connections are used in buildings to support gravity loads and function as part of lateral load resisting systems. In addition, they are used for mounting of equipment and in outdoor support structures, where they may be affected by vibration and fatigue due to wind loads. Base plates and anchor rods are often the last structural steel items to be designed but the first items are required on the jobsite. The schedule demands along with the problems that can occur at the interface of structural steel and reinforced concrete make it essential that the design details take into account not only structural requirements but also include consideration of constructability issues, especially anchor rod setting procedures and tolerances. The importance of the accurate placement of anchor rods cannot be over-emphasized. This is one of the key components to safely erecting and accurately plumbing the building. The material in this Guide is intended to provide guidelines for engineers and fabricators to design detail and specify column-base-plate and anchor rod connections in a manner that avoids common fabrication and erection problems. This Guide is based on the 2005 AISC specification for structural steel buildings ( AISC, 2005 ) and it includes guidance for designs made in accordance with load and resistance factor design ( LRFD ) or allowable stress design ( ASD ). This Guide follows the format of the 2005 AISC specification for developing strength parameters for foundation system design in generic terms that facilitate either load and resistance factor design (LRFD) or allowable strength design ( ASD ). Column bases and portions of the anchorage design generally can be designed in a direct approach based on either LRFD or ASD load combinations. The one area of anchorage design that is not easily designed by ASD is the embedment of anchor rods into concrete. This is due to the common use of ACI 318 Appendix D, which is exclusively based on the strength approach ( LRFD ) for the design of such embedment. Other steel elements of the foundation system, including the column base plate and the sizing of anchor diameters are equally prescient to evaluation using LRFD or ASD load methods. In cases such as anchors subjected to neither tension nor shear, the anchorage development requirement may be a relatively insignificant factor. The generic approach in development of foundation design parameters taken in this Guide permits the user a choice to develop the loads based on either the LRFD or ASD approach. The derivations of foundation design parameters, as presented here in, are either multiplied by the resistance factor, φ or divided by a safety factor, Ω based on the appropriate load system utilized in the analysis consistent with the approach used in the 2005 specification. Many of the equations shown herein are independent of the load approach and thus are applicable to either design methodology. These are shown in singular format. Other derived equations are based on the particular load approach and presented in a side - by - side format of comparable equations for LRFD or ASD application. The material selection and design details of base plates can significantly affect the cost of fabrication and erection of steel structures, as well as the performance under load. Relevant aspects of each of these subjects are discussed briefly in the next section. It is not only important to design the column-base-plate connection for strength requirements, but also important to recognize that these connections affect the behavior of the structure. Assumptions are made in structural analysis about the boundary conditions represented by the connections. Models comprising beam or truss elements typically idealize the column base connection as either a pinned or fixed boundary condition. Improper characterization can lead to error in the computed drifts, leading to unrecognized second-order moments if the stiffness is over estimated, or excessive first-floor column sizes if the stiffness is underestimated. If more accurate analysis is desired, it may be necessary to input the stiffness of the column-base-plate connection in the elastic and plastic ranges, and for seismic loading, possibly even the cyclic force deformation relations. The forces and deformations from the structural analyses used to design the column-base plate connection are dependent on the choice of the column base-plate connection details.

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