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Analysis of results of molasses tanks settlement testing G. Grget a,⇑, K. Ravnjak a, A. Szavits-Nossan b a Geokon-Zagreb, Zagreb, Croatia b University of Zagreb, Faculty of Civil Engineering, Zagreb, Croatia Received 16 February 2017; received in revised form 28 May 2018; accepted 3 July 2018 Available online 28 September 2018 Abstract Two molasses tanks, each with a capacity of 6330 m3, were built at a distance of 200 m from the river Sava on soft swamp sediments with poor geotechnical characteristics. The foundations of the tanks are a form of reinforced concrete slab built on the soil improved with vertical drains. The monitoring of settlement for each tank involved measuring the settlement using a horizontal inclinometer placed on the reinforced concrete slab and permanent geodetic points. Measured settlement curves are presented and used for comparison with the designed curves. 2018 Production and hosting by Elsevier B.V. on behalf of The Japanese Geotechnical Society. Keywords: Steel tank; Settlements; Vertical drains; Back-calculation; Monitoring; Horizontal inclinometer منبع Analysis of results of molasses tanks settlement testing.pdf

Design control and monitoring of a jet grouted excavation bottom plug طراحی و کنترل های عملیات جت گروتینگ در ایستگاه های زیرزمینی N. Eramo & G. Modoni University of Cassino, Cassino, Italy M. Arroyo Alvarez de Toledo Universidad Politécnica de Catalunya, Barcelona, Spain ABSTRACT: Jet grouting is adopted in different geotechnical conditions to ensure provisional earth retaining and waterproofing functions in excavations. Despite careful theoretical models available to predict the mechanical response of these structures, design is often carried out without adequate control, i.e. by assuming ideal effectiveness of ground improvement. On the contrary, adverse effects have been documented by past experiences which can be traced back to erroneous prediction of treatments effects, inaccurate control of the execution or to unexpected responses of the surrounding environment. All these uncertainties, which are critical when working in urban areas, can be minimized by detailed preliminary field trials, accurate treatment execution control and a prompt monitoring of the surrounding area. The present paper illustrates these issues with a description of the design and execution of a massive jet grouting bottom plug forming the base of a large excavation for a tube station. The results of preliminary field trials are summarized to directly compare the effectiveness of different injection systems and introduced in statistical design analyses of the jet grouted structure. A detailed investigation of the surface movements induced by injections is also reported. To this aim, the evolution of displacements recorded around trial columns and on the area surrounding the excavation is mapped to evaluate the effects of the different adopted injection techniques. منبع Design_control_and_monitoring_of.pdf