Foundations towers, guyed

When the tower is very high, it is sometimes desirable to maintain stability by means of guy wires rather than a large foundation. Although it is not uncommon to find two or even three sets of guy wires on one stack, towers seldom have more than one set, and even these are rare. This discussion, therefore, will be confined to towers with one set of guy wires. 

Four guy wires are usually used for each set, although in some instances three, and in others as many as six have been used. They are attached to a rigid collar which is located at a point approximately 2/3 (sometimes 3/4) of the tower height above the foundation. 

It was shown by equation (11-1) that the total soil loading, to be considered in the design of tower foundations, is the sum of Si, the dead load, and S2, the load caused by the overturning or wind moment. There is no overturning moment on guyed towers however, the wind pressure does have an important effect on the foundation, as the soil is required to resist the vertical component of the pull on the guy wires. 

Foundation bolts for guyed towers are required to resist the shearing action of the wind pressure at the base of the tower. It is obvious that ample allowance should be made in the size of the bolts to provide for the initial tension caused by tightening the nuts and for corrosion. 

Examples of marine foundation types—(d) typical tension leg structure and (e) guyed tower structure. (From Gibson, R.E. and Dowse, B.E.W., Canadian Geotech. /, 18 171-178,1981. Reprinted with permission of Canadian Geotechnical Journal.)... 

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