Note for Hoek Brown Model in Geotech.pptx

Hoek-Brown Note

1. For axisymmetric structures like chimneys, storage tanks, silos, and transmission-line towers, the ring footing is frequently used as a foundation. The ring footing is also referred to as annular footing, and it is more cost-effective than circular footing as it uses less material and has the added benefit of arching. It is vital to have a comprehensive understanding of the bearing capacity of ring footings for a safe and cost-effective design. The ring footing is defined by a radii ratio which is the ratio Griffiths (1982, 1989) presented the application of finite element method (FEM) for the computation of collapse loads and bearing capacity factors for strip footing. Subsequently, the bearing capacity factors have been evaluated by the FEM and the finite difference method (FDM) using fast Lagrangian analysis of continua (FLAC) for the strip footing, circular footing, ring footing and even for the footing with irregular shape and geometry (Sloan and Randolph 1982; Burd et al. 1989; Manoharan andDasgupta 1995; Frydman and Burd 1997; Ericksonand Drescher 2002; Boushehrian and Hataf 2003;Majidi and Mirghasemi 2008; Keshavarz et al. 2011;Haghbin and Ghazavi 2013; Rostami and Ghazavi2015).

2. The lowest portion of structures that transmits its weight to the fundamental soil is the foundation. Shallow foundations comprise many types. The suitable type is chosen according to the structure that the footing will carry. One of the types is the ring footing that used in structures that have circular or r round planes also all loads transmit by the wall to the foundation and end to the soil. Oil tanks, tall transmission tower, and silos all these structures are supporting on ring foundation and exposure to horizontal load (wind load),as well as vertical load the combining between these loads, cause inclined load, place of horizontal loads at any point along with the elevation of structures cause eccentricity load, the bearing capacity of foundations varies with the shape of the footing, soil limitations, and loading states. The purpose of a ring footing is to distribute the weight of the building evenly across the ground and to prevent settling or sinking of the structure. The ring footing is typically placed around the perimeter of the building or structure, creating a continuous circular foundation. Ring footing plans are commonly used in the construction of large buildings or structures with irregular shapes, where the weight of the structure needs to be evenly distributed across the ground. The design of a ring footing plan is typically based on the size and weight of the building or structure, as well as the soil conditions at the construction site. The construction of a ring footing plan typically involves excavating the ground to create a circular trench or foundation, and then pouring concrete into the trench to create the foundation. The size and depth of the foundation will depend on the weight of the building or structure and the soil conditions at the construction site.