Soilbags are usually incorporated into temporary structures, rather than being used in conventional construction, as they have a tendency to deteriorate rapidly on prolonged exposure to sunlight. The amazing bearing capacity of soilbags has, however, inspired the development of an earth reinforcement method in which the bearing capacity of soft foundations is enhanced, reaching ten per cent of that of concrete. New methods have seen their projected durability as a semi-permanent material extend to in excess of fifty years, provided that direct exposure to sunlight and ultra-violet rays is avoided.
This book covers the development, properties and characteristics of soilbags, as well as design features of structures built by this method. The geotechnical applications in, for example, railway ballast foundation reinforcement, retaining walls and embankment constructions are extensively described and richly illustrated by reference to case studies from Japan. The intention is to stimulate a wider, international adoption of the method in earth reinforcement and civil engineering construction, with particular reference to developing countries. Geotechnical and foundation engineers and other professionals working on earth reinforcement will find this a valuable work, while it will provide supplementary information to graduate students in soil mechanics and foundation engineering.
Nagoya Institute of Technology, Japan Hohai University, Nanjing, China
Preface 1 Why do we study soilbags now? 2 How to achieve earth reinforcement with soilbags (Solpack method)? 3 Characteristics of soilbags 3.1 Compressive strength and anisotropy 3.1.1 Compressive strength in the case of ? = 0 3.1.2 Strength anisotropy in the case of ? ? ? 0 3.2 Vibration reduction 3.2.1 Laboratory cyclic simple shear tests 3.2.2 Laboratory vibration tests 3.2.3 In situ vibration tests 3.2.4 Case history study 3.2.5 Quake-absorbing structures 3.3 Frost heave prevention 3.4 Tensile strength 3.5 Failure criterion 3.6 Deformation 3.6.1 Deformation estimation when soilbags are subjected to major principal stress along the short axis of soilbags (? = 0) 3.6.2 Deformation estimation when soilbags are subjected to major principal stress with an inclination to the short axis of soilbags (? ? ? 0) 3.7 Friction between soilbags 4 Design approaches of the Solpack method 4.1 Embankment constructed with soilbags 4.2 Reinforcement of soft ground with soilbags 4.3 Retaining walls built with soilbags 5 Applications of the Solpack method 5.1 Railway ballast foundations 5.1.1 Verification through laboratory experiments 5.1.2 Applications to a local Japanese Railway 5.2 Soft foundation reinforcement 5.2.1 In YC cho, Ibaraki Prefecture 5.2.2 In FS-cho, Ibaraki Prefecture 5.2.3 In MB city, Chiba Prefecture 5.2.4 In KR-cho, Chiba Prefecture 5.2.5 In S City, Miyagi Prefecture 5.2.6 In TK city, Hokkaido 5.2.7 In OT city, Hokkaido 5.2.8 In ST city, Osaka 5.2.9 Reinforcement for elevator foundation in K city, Kyoto 5.3 Soilbag piles 5.3.1 Principle of soilbag piles 5.3.2 Applications of soilbag piles 5.4 Retaining wall 5.4.1 Restoration of a sliding slope in Fukuoka Prefecture 5.4.2 Retaining wall in NO city, Aichi Prefecture 5.4.3 Retaining wall in MS city, Shizuoka Prefecture 5.4.4 Restoration works in Miyake Island, Japan 5.5 Tunnel lining 5.5.1 Loading tests on an arch structure model constructed with soilbags 5.5.2 Construction of a trial arch structure 6 Natural vegetations planted in soilbags 6.1 Growth of native vegetation cuttings in soilbags 6.2 Spontaneous germination of vegetation seeds in soilbags filled with slope mantle soils 7 Concluding remarks References