326
3680.001
Devalapura, Ravi K.; Gary L. Krause; Maher K. Tadros
TMS Journal
Article
The Masonry Society
1994
February
46-59
Y
In the past, retaining walls were exclusively constructed using reinforced concrete, traditional reinforced masonry, and timber. The construction of reinforced concrete walls such as CIP concrete and traditional masonry demand both time and skilled labor. Timber deteriorates with time and allows moisture penetration, once it is subjected to splitting and cracking. Also, these systems are rigid structures and cannot accommodate significant differential settlements.The recent development of Mechanically Stabilized Earth (MSE) systems has given designers another choice in designing a slope stabilization system that best suits their need in a cost-effective manner. The MSE systems have been increasingly used since 1986 and since then, the number of masonry retaining wall construction has grown up well over 5,000 in North America. The masonry retaining wall system is a part of mechanically stabilized earth systems in which masonry block modules are used for the facing. These blocks can be made of high-strength, high-density concrete to resist cracking and erosion. Since these are mass produced in the plants, high quality control and economy can be achieved. Simple connection mechanisms such as keys, lips, or pins allow fast mortarless erection. No special skills or equipment are required for assembly. Light compactors may be requiredonly to compact the backfill soil. Most of the systems are designed to last at least 50 years and require little or no maintenance. Each masonry block weights from 30 to 100 pounds (approximately), allowing workers to place them by hand or light crane. Reinforcement may or may not be required depending on the height of the wall.
This paper includes most of the systems available (NCMA members) at present. A survey was conducted by the authors, and eleven manufacturers responded from the list of thirteen licensers at NCMA. Some of the sections in these paper include a general description of the reinforced soil system, since the design procedure for masonry retaining walls is basically taken from the conventional retaining wall design. Fig. 1 shows a typical cross section of a reinforced soil system. Some of the common applications of reinforced soil are in the following areas: retaining walls or retained embankments, wing walls, highways, urban housing, underground and parking structures, industrial bulk storage structures, and foundations for structures.