One characteristic of masonry structures in general, and stone arch bridges specifically, is the fact that the person(s) who built the bridge inevitably left behind a hallmark. Not just any and all plaques, but the workmanship itself is often telltale. Each builder has his own method, and, in the case of bridge contractors, the contracting company itself had its own method. Walter Sharp Walter Sharp, who built many bridges in Kansas, generally used large, chunky blocks of stone, not … [Read more...] about Stone Arch Bridges: Who Built It?
When building a stone arch bridge, the question sometimes arises as to how many arches are needed. In some cases the answer is obvious; for instance, a small gap begs for only one arch. But there are times when multiple arches are advantageous, despite the fact that a pier in the waterway is required. First, it is important to understand the limitations inherent to stone arches. An arch between 2 feet and 20 feet is fairly easily made and does not present major design challenges. Nor does … [Read more...] about Stone Arch Bridges: Spans and How Many?
It is often desired to build a stone arch bridge. Such a structure is scenic and, of course, lends a fine touch to landscaping. The question is how do you go about doing it? We have provided this short guide as a very general rule of thumb; the details of your construction will vary. We’ve based it on a small footbridge we built, including some lessons learned afterwards from the process. We assume no liability for use or misuse of this information, but we do hope this will be helpful to the … [Read more...] about Building a Stone Arch Bridge
When building bridges, it is always necessary to take into account the hydraulic effects of the structure. Piers in a river, for instance, always cause interesting water-related phenomena. Not only is a pier vulnerable to being undermined by the action of water, a pier can obstruct trees and other floating objects in the river until an effective dam is created, unless precautions are taken. In extreme cases, like the old London Bridge, too many too-wide piers can pose a major obstruction of … [Read more...] about The Hydraulic Properties of Stone Arch Bridges
There is still a great urge to build stone arch bridges. Not, perhaps, on the massive scale of old, but as attractive, durable footbridges over small streams. When done right, the results are quite rewarding, and the building process itself can be enjoyable. Furthermore, a stone arch bridge should need but little maintenance, especially compared to wooden structures. One of the main considerations to think about is: how thick should the arch ring be? Calculating the Arch Ring The … [Read more...] about Building Stone Arch Bridges: Arch Thickness
The foundations of a stone arch bridge are the single most important factor in determining the life of the bridge. If the foundations are good, the bridge can last for centuries — or even a millennium! If the foundations are bad, the bridge may last but a few years, or even a few months. Failure of the foundations is by and large the most common cause of stone arch bridge failures. Curiously, stone arch bridges frequently have but shallow foundations. Setting the bridges a short distance … [Read more...] about Stone Arch Bridges: Foundations
Possibly one of the more mystifying elements of stone arch bridges is the manner by which they are constructed. While it may be easy enough to see that the arch stands because of every stone pushing against its neighbor, the obvious question is, “How do the stones stay in place before they are all stacked up?” The short answer is they don’t. Or, rather, they wouldn’t … on their own. A temporary formwork of some type must be built before the stones are in place. The arch depends on all of the … [Read more...] about How Arch Bridges Are Built