Deep mixing method using cement hardening agent

116A The marine clay underlying the new Changi International Airport was consolidated using Geodrains and surcharge. A pilot test was carried out to enable the selection of the most suitable method of soil treatment and to determine the design soil parameters. This paper describes the design procedure and the acceptance criteria for main works. Typical results from the pilot test and the main works are presented. The phenomenon of a back pressure effect and stagnation of high excess pore pressure occurring with continuing ground settlement is discussed. 843335 Improvement of a site by preloading Colleselli, F; Mazzucato, A; Previatello, P Proc lOth International Conference on Soil Mechanics and Foundation Engineering, Stockholm, 15-19 June 1981 V3, P627-632. Publ Rotterdam: ,4. ,4. Balkema, 1981 Preloading fills are commonly used to improve soil conditions in the Po Valley, Italy. In the case considered, the soil characteristics were analysed before and after preloading and soil behaviour was monitored using piezometers, settlement gauges and vertical inclinometers. 843336 Consolidation of clay cores of high dams (In French) Dingozov, G; Germanov, T Proc lOth International Conference on Soil Mechanics and Foundation Engineering, Stockholm, 15-19 June 1981 V3, P645-648. Publ Rotterdam: A. .4. Balkema, 1981 843337 Chemical stabilisation of loess, New Zealand Evans, G L; Bell, D H Proc lOth International Conference on Soil Mechanics and Foundation Engineering, Stockholm, 15-19 June 1981 V3, P649-658. Publ Rotterdam: A. A. Balkema, 1981 Stabilization of Port Hills loess with (1) phosphoric acid and (2) lime was investigated using standard laboratory compaction techniques and field trials.

843338 Experiments with chemical soil treatments in Hungary (In French) Gaspar, L Proc lOth International Conference on Soil Mechanics and Foundation Engineering, Stockholm, 15-19 June 1981 V3, P663-664. Publ Rotterdam: A. A. Balkema, 1981

843339 Measurement of autogenous healing in stabilized soils Hammond, A A Proc 10th International Conference on Soil Mechanics and Foundation Engineering, Stockholm, 15-19 June 1981 V3, P671-676. Publ Rotterdam: A. A. Balkema, 1981 Describes a laboratory study of autogenous healing using a lateritic soil, lime and cement. The stress/strain properties of the stabilized soil specimens were measured after periods of initial curing. The tested specimens were further cured for various periods and a second stress/strain measurement undertaken. The autogenous healing was then computed. From the results of the study it was found that short initial curing periods and long curing periods after flawing enhanced the healing process. It is inferred from the study that beyond seven days curing a lime or cement stabilized base over stressed to failure will not heal up but deteriorate. Light traffic may be allowed however, within seven days of laying a lime or cement stabilized base without danger of any flaws being healed up later.

84334O Consolidation of fine-grained soils by prefabricated drains Hansbo, S Proc 10th International Conference on Soil Mechanics and Foundation Engineering, Stockholm, 15-19 June 1981 V3. P677-682. Publ Rotterdam: A. A. Balkema. 1981 Presents a simple solution for the calculation of consolidation of fine-grained soils by drain wells with regard to well resistance and smear. A parametric study is made with regard to the effect of discharge capacity of various drain types and to the effect of smear. Prefabricated band-shaped drains are discussed and their efficiency is compared with that of sand drains. Discharge capacity values ofdifferent prefab drains obtained in laboratory tests are presented. Filter requirements are analysed. 843341 Improvement of a quick sand Hanzawa, H Proc lOth International Conference on Soil Mechanics and Foundation Engineering, Stockholm, 15-19 June 1981 V3. P683-686. Publ Rotterdam: A. A. Balkema, 1981 Quick sand is characterized by potential liquefaction failure under static shear conditions. The paper describes the undrained strength of the quick sand and reports the change in shear characteristics through soil improvement using the Dynamic Consolidation method. 843342 Soil improvement by lime-fly ash slurry injection Joshi, R C; Natt, G S; Wright, P J Proc lOth International Conference on Soil Mechanics and Foundation Engineering, Stockholm, 15-19 June 1981 V3, P707-712. Publ Rotterdam: A. A. Balkema. 1981 The use of lime and lime-fly ash slurry injection techniques, for deep in situ stabilization offine grained soils is described. A case history on pressure injection ofsubgrade soils to a depth of 13m, with lime and lime-fly ash slurry is presented. Laboratory test data indicate that lime slurry injection processes may be used to improve shear strengths of soft clay soils. Auth. 843343 Studies of electrochemical hardening of marine clay Katti, R K; Dongarwar, D W; Patwardhan, S H Proc 10th International Conference on Soil Mechanics and Foundation Engineering, Stockholm, 15-19 June 1981 V3, P717-720. Publ Rotterdam: A. A. Balkema, 1981 843344 Deep mixing method using cement hardening agent Kawasaki, T; Niina, A; Saitoh, S; Suzuki, Y: Honjyo, Y Proc lOth International Conference on Soil Mechanics and Foundation Engineering, Stockholm, 15-19 June 1981 V3, P721-724. Publ Rotterdam: A. A. Balkema, 1981

A deep mixing method using cement slurry as a hardening agent, a new method of soil stabilization, is explained. This report describes the features of the method, the deep mixing machine of great importance for this stabilization method, the physical and mechanical properties of the improved soil for which cement slurry had been used, and at the end, two cases of actual application of this method. Auth. 843345 Use of by-products in foundation engineering Lychko, Y M; Pevzner, M E; Belenky, N G; llyina, N G; Zagovora, G A Proc lOth International Conference on Soil Mechanics and Foundation Engineering, Stockholm, 15-19 June 1981 V3, P733-734. Publ Rotterdam: A. A. Balkema, 1981