Contribution to the design history of the gravity wall

Contribution to the design history of the gravity wall

SURFACE STRUCTURES:BASE COURSES 127A Soil reinforcement method is a relatively new ground improvement technique which strengthens weak area of groun...

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SURFACE STRUCTURES:BASE COURSES

127A

Soil reinforcement method is a relatively new ground improvement technique which strengthens weak area of ground using inclusions whose material properties are known. In this paper two different types of soil reinforcement techniques are introduced. They are micropiling reinforcement and deep mixing method or DMM. For the first type, a case study and performance during construction evaluated numerically. A case study which utilizes the DMM is also discussed. (from Author)

This paper describes the methods envisaged at the design stage for junctioning the downstream end of the new Cairo sewer system with the Distribution Chamber (DC) constructed as part of the new Ameria pumping station complex. This required the construction of a machine reception chamber, but the tunnel machine arrived before the chamber could be constructed, which created major problems and constructional changes. Eventually freezing techniques were adopted to enable a short tunnel to be driven out from the DC to the tunnel machine and an in situ R.C. junction to be made in 'free air'. The internal parts of the abandoned tunnel machine were cut up and removed piecemeal, whilst the skin was left in place to form the back shutter to the internal in situ R.C. lining. Thereafter the secondary lining from the end of the existing tunnelled sewer into the DC was constructed as originally envisaged. (Author)

Soil stabilisation

SURFACE STRUCTURES

953171 Slope stabilization using vegetation Tien H. Wu, in: Geotechnical engineering: emerging trends in design and practice, K.R. Saxena, (Balkema), 1994, pp 377403.

General

953170 Case studies of reinforced ground with micropiling and other improvement technique M. Kamon, in: Prediction versus performance in geotechnical engineering. Proc. symposium, Bangkok, 1992, ed A.S. Balasubramaniam & & others, (Balkema), 1994, pp 115-125.

The stability of slopes is governed by the load, which is the driving force that causes failure, and the re~/stance, which is the strength of the soil-root system. The weight of trees growing on a slope adds to the load but the roots of trees may serve as a soil reinforcement and increase the resistance. Vegetation may influence slope stability indirectly through its effect on the soil moisture regime. Vegetation intercepts rainfall and draws water from the soil via evapotranspiration. This reduces soil moisture and pore pressure, increases the shear strength of the soil, and increases the resistance. Vegetation roots tend to increase soil permeability and increase infiltration and soil moisture, while the organic layer associated with vegetative cover tends to retard infiltration. The objective of this paper is to outline the methods that may be used to evaluate the influence of these factors on slope stability. Emphasis is placed on the mechanics of slope stability. (from Author)

953172 Evaluation of water and gas transport in layered soil covers for coal ash deposits: 2D-calculations and impact of a weak zone

M. Lindgren & A. Rasmuson, Water, Air, & Soil Pollution, 77(1-2), 1994, pp 97-114. Disposed coal ash may constitute a future environmental problem due to large quantities and its content of heavy metals. One method to reduce the leaching from a deposit is to use a soil cover. The soil cover should primarily act as a barrier for infiltrating water but may also reduce the amount of oxygen reaching the waste. The latter is of importance for the solubility of many trace metals, since more oxidizing conditions tend to increase the solubility. A methodology for evaluating the efficiency of a soil cover to reduce water infiltration and gas transport is discussed. Consisting of two layers, a tight layer and a protecting layer. Simulations show that slope has a minor impact, while the hydraulic conductivity of the tight layer is of major importance. (from Authors)

Ground freezing 953173 Amerin tunnel junction using the freezing technique G. R. Flint, in: Tunnelling and ground conditions. Proc. congress, Cairo, 1994, ed M.E.A. Salam, (Balkema), 1994, pp 117-126.

953174 Contribution to the design history of the gravity wall P. Ventura, in: Prediction versus performance in geotechnical engineering. Proc. symposium, Bangkok, 1992, ed A.S. Balasubramaniam & & others, (Balkema), 1994, pp 263-269. The paper tries to merge acquired values of old technical criteria with that of innovation. Purpose is tested by examining design evolution and the safety control of the gravity wall and back-analysis some old and recent observed works. (Author) 953175 M o r t a r deterioration of the masonry walls in historic bnildings. A case history: Vanvitelli's Mole in Ancona G. Moriconi, M. G. Castellano & M. Collepardi, Materials & Structures, 27(171), 1994, pp 408-414. The utilization of data from advanced techniques, such as enhanced pattern treatment of X-ray diffraction analysis, combined with data from historical sources as well as environmental information, has been applied to diagnose the complex deterioration mechanisms of a historic construction. A case history is provided dealing with a famous Italian construction in Ancona designed and erected by the Neapolitan architect Luigi Vanvitelli during 1733-1743, where both jointing and rendering mortars deteriorated very seriously. It has been found that the original iime-pozzolan mortar deteriorated due to physical events (rain water leaching, thermal changes, freezing-thawing, etc.), whereas Portland cement mortars, used to repair damaged walls, deteriorated by chemical sulfate attack. (Authors)

Base courses and pavements 953176 Repeated-load response of aggregates in relation to track quality index G. P. Raymond & R. J. Bathurst, Canadian Geotechnical Journal, 31(4), 1994, pp 547-554. Track quality rating systems are briefly introduced as a background for undertaking a study of the repeated-load response of ballast aggregates. The results from a number of different laboratory investigations are reviewed and this data interpreted in terms of track quality behaviour. The paper reviews selected results from repeated-load triaxial tests used to investigate the repeated-loading response of different granular railway ballasts at stress levels comparable with those below North America heavy freight axle loads. These results are used to establish an aggregate index to predict