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Modern Methods of Excavation Support Groundforce shorco company منبع @Civilbest, Excavation Safety Presentation - Feb 2013pdf.pdf

Application of the Hardening Soil model in deep excavation analysis The Mohr–Coulomb model (MC) is commonly used in deep excavation analysis for its simplicity. However, it has shortcomings that may produce unrealistic soil behaviour. The Hardening Soil model (HS) is an advanced soil model that is able to generate more realistic soil response in terms of non-linearity, stress dependency and inelasticity. This article highlights some of the shortcomings of the MC model and presents a simplified approach to determine the HS parameters for drained and undrained analysis of deep excavations. Three case studies were back-analysed to validate the application of the HS model for practical excavation analysis. The HS model suffers the same problems as the MC model in using effective stress parameters c0 and f0 to determine the undrained shear strength. Keywords: Hardening Soil model; Mohr-Coulomb soil model; excavation; constitutive model; nonlinearity; backanalysis منبع hs&mc.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

روش های عمومی پایدارسازی گودها در محیط های شهری ارایه ای از دکتر سیاوش لیتکوهی همایش ایمنی در گودبرداری - 27 آذر 1392 فایل ارایه سمینار در فرمت پی دی اف در 59 اسلاید شامل مطالب زیر : روش های عمومی پایدارسازی گود در محیط های شهری مباحث عمومی گودبرداری در محیط های شهری ریزش گودهای شهری روش های رایج پایدارسازی در محیط های شهری به نقل از کانال تلگرام CIVILCA دانلود از پیوست پایدارسازی گودها در محیط شهری.part1.rar پایدارسازی گودها در محیط شهری.part2.rar

The Investigation of Various Kinds of Guardian Structures, their Economics and Technical Comparison in Some of Under Construction Buildings in Ahwaz City. Abbasi Dezfouli A., Seyed Aghamiri S.T. J. Civil Eng. Urban., 5(1): 01-06, 2015; pii:S225204301500001-5 Abstract Lack of planting guardian structure in the time of drilling and excavation in high-density spots of urban is one of the issues that bring life and financial losses. In this study, various kinds of planting guardian structures by using a series of vast studies and interviewing with expert executives in different dimensions specifically it has been investigated from the point of view of construction management and has been considered the special environmental status of the city of Ahwaz. The present study is kind of a fundamental one that firstly it has been collected by studying the researches and updated articles, the presented instructions about the construction management and execution of guardian structure, and then documenting of information has been done by studying and through surveying of under construction structures, ultimately consulting with the executives and prominent professors has led us to provide solutions for choosing the best suited methods of guardian structures both economic and technical. The results of this research indicate that for any depth of excavation up to 10 meters regarding to the type of soil and the level of underground water, the suited guardian structure which is economic and technical among different methods, truss guardian structure and Reciprocal inhibition for different excavation surfaces is a good solution for the issue of construction in Ahwaz. Keywords: Guardian Structure, Excavation, Inhibition, Construction Management [Full text-PDF] منبع: [Hidden Content] J. Civil Eng. Urban., 5 (1) 01-06, 2015.pdf

Optimization the Distance between Piles in Supporting Structure Using Soil Arching Effect Original Article, C57 HosseinianS. and Cheraghi Seifabad M Journal. Civil Eng. Urban. 3(6):386-391. 2013 ABSTRACT:High cost value of traditional methods for stabilization of pit, encouraged the engineers to study more about soil characteristics and its application. Arching effect is one of these characteristics, it allows to designers apply non-continuous structural elements to provide safety and economy of project. To investigate arching effect of retained structure with anchorage method, Plaxis 3D Tunnel software is used to model fine-grain (CL-ML) with hardening soil behaviour which simulate soil material. In first model, the distances between piles are 2m and number of anchors are 5. In second model, the distance between piles are 4m and number of anchors are 3. The numerical modeling results show horizontal arching appearance in distance between piles. A comparison between the results gained from the 3D FE analyses and the more or less conventional method shows that the classical method is very much on the safe side. Keywords:Arching effect; Excavation; Anchorage method; Plaxis 3D Tunnel software منبع: [Hidden Content] دانلود: [Hidden Content].,57-386-391.pdf J. Civil Eng. Urban.,57-386-391.pdf