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Earth Pressure (earth + pressure)

Distribution by Scientific Domains
Engineering100%

Kinds of Earth Pressure

  • the earth pressure
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    Selected Abstracts

    Verdichtungserddruck bei leichter Verdichtung

    BAUTECHNIK, Issue 3 2008
    Dietrich Franke Univ.-Prof. i. R. Dr.-Ing. habil.
    Der Erddruck auf hinterfüllte Wände wird durch die Verdichtung der Hinterfüllung erhöht. In vielen Fällen reicht eine leichte Verdichtung zur Vermeidung größerer Setzungen aus. In Auswertung entsprechender Erddruckmessungen, die in der Vergangenheit in Stuttgart und Dresden durchgeführt wurden, lassen sich die Angaben der neuen DIN 4085 für leichte Verdichtung ergänzen, wenn bestimmte Einschränkungen bei der Auswahl der Verdichtungsgeräte eingehalten werden. Earth pressure due to light compaction. The earth pressure acting on backfilled walls is increased by compaction. A light compaction suffices in many cases to prevent larger settlements. Earth pressure measurements were performed in the past in Stuttgart and Dresden. Based on these measurements, the specifications of the new DIN 4085 are complemented for light compaction. [source]

    Study on the action of the active earth pressure by variational limit equilibrium method

    INTERNATIONAL JOURNAL FOR NUMERICAL AND ANALYTICAL METHODS IN GEOMECHANICS, Issue 10 2010
    Li Xinggao
    Abstract Within the framework of limiting equilibrium approach, the problem of active earth pressure on rigid retaining wall is formulated in terms of the calculus of variations by means of Lagrange multipliers. It is transcribed as the functional of extreme-value problem by two undetermined function arguments, and is further transformed into determining the minimax solution of restrained functions incorporating the geometrical relations of the problem. The function of (fmincon) in the optimization toolbox of MATLAB 6.1 can be used to find the minimax solution. Computation results show there exist two kinds of modes of failure sliding along plane surface and rotating around log-spiral cylinder surface when the soil behind the walls reaches the critical active state. The magnitude of active earth pressure in the case of translational mode is less than that in the case of rotational mode. The location of action point of earth pressure in the case of translational mode is at or below height of the wall, and in the case of rotational mode, is above height of the wall. Preliminary study indicates a pair of numbers by two theoretical modes can be regarded as an interval estimation of active pressure. Copyright © 2009 John Wiley & Sons, Ltd. [source]

    Lateral force and centroid location caused by horizontal and vertical surcharge strip loads on a cross-anisotropic backfill

    INTERNATIONAL JOURNAL FOR NUMERICAL AND ANALYTICAL METHODS IN GEOMECHANICS, Issue 13 2007
    Cheng-Der Wang
    Abstract This work presents analytical solutions for determining lateral force (force per unit length) and centroid location caused by horizontal and vertical surcharge surface loads acting on a cross-anisotropic backfill. The surcharge loading types are point load, line load, uniform strip load, upward linear-varying strip load, upward nonlinear-varying strip load, downward linear-varying strip load, and downward nonlinear-varying strip load. The planes of cross-anisotropy are assumed parallel to the backfill ground surface. The proposed solutions, derived by integrating the lateral stress solutions (Int. J. Numer. Anal. Meth. Geomech. 2005; 29:1341,1361), do not exist in literature. Clearly, the type and degree of material anisotropy, loading distance from the retaining wall, and loading types markedly impact the proposed solutions. Two examples are utilized to illustrate the type and degree of soil anisotropy, and the loading types on the lateral force and centroid location in the isotropic/cross-anisotropic backfills generated by the horizontal and vertical uniform, upward linear-varying and upward nonlinear-varying strip loads. The parametric study results demonstrate that the lateral force and centroid location accounting for soil anisotropy, loading distance from the retaining wall, dimension of the loading strip, and loading directions and types differ significantly from those estimated using existing isotropic solutions. The derived solutions can be added to other lateral pressures, such as earth pressure or water pressure, required for stability and structural analysis of a retaining wall. Additionally, they can simulate realistically actual surcharge loading problems in geotechnical engineering when backfill materials are cross-anisotropic. Copyright © 2007 John Wiley & Sons, Ltd. [source]

    The influence of the construction process on the deformation behaviour of diaphragm walls in soft clayey ground

    INTERNATIONAL JOURNAL FOR NUMERICAL AND ANALYTICAL METHODS IN GEOMECHANICS, Issue 7 2006
    R. Schäfer
    Abstract Conventional numerical predictions of deep excavations normally neglect the construction process of the retaining structure and choose the earth pressure at rest as initial condition at the beginning of the simulation. The presented results of simulation and measurements during the construction process of the Taipei National Enterprise Center show, that such an assumption leads to an underestimation of the horizontal wall deflection, the surface ground settlements as well as the loading of the struts in case of normally to slightly over-consolidated clayey soil deposits. The stepwise installation process of the individual diaphragm wall panels results in a substantial modification of the lateral effective stresses in the adjacent ground. Especially the pouring process of the panel and the fresh concrete pressure causes a partial mobilization of the passive earth pressure and a distinct stress level increase in the upper half of the wall. As a consequence of the increased stresses prior to the pit excavation, up to 15% greater ground and wall movements are predicted. Moreover, the increased stress level due to the installation process of the diaphragm wall leads to substantial higher strut loadings during the excavation of the pit. Copyright © 2006 John Wiley & Sons, Ltd. [source]

    Modelling of earth and water pressure development during diaphragm wall construction in soft clay

    INTERNATIONAL JOURNAL FOR NUMERICAL AND ANALYTICAL METHODS IN GEOMECHANICS, Issue 13 2004
    R. Schäfer
    Abstract The influence of a diaphragm wall construction on the stress field in a soft clayey soil is investigated by the use of a three-dimensional FE-model of seven adjacent wall panels. The installation procedure comprises the excavation and the subsequent pouring of each panel taking into account the increasing stiffness of the placed fresh concrete. The soft clay deposit is described by a visco-hypoplastic constitutive model considering the rheological properties and the small-strain stiffness of the soil. The construction process considerably affects the effective earth and pore water pressures adjacent to the wall. Due to concreting, a high excess pore water pressure arises, which dissipates during the following construction steps. The earth pressure finally shows an oscillating, distinct three-dimensional distribution along the retaining wall which depends on the installation sequence of the panels and the difference between the fresh concrete pressure and the total horizontal earth pressure at rest. In comparison to FE-calculations adopting the earth pressure at rest as initial condition, greater wall deflections and surface ground settlements during the subsequent pit excavation can be expected, as the average stress level especially in the upper half of the wall is increased by the construction procedure of the retaining structure. Copyright © 2004 John Wiley & Sons, Ltd. [source]

    Verdichtungserddruck bei leichter Verdichtung

    BAUTECHNIK, Issue 3 2008
    Dietrich Franke Univ.-Prof. i. R. Dr.-Ing. habil.
    Der Erddruck auf hinterfüllte Wände wird durch die Verdichtung der Hinterfüllung erhöht. In vielen Fällen reicht eine leichte Verdichtung zur Vermeidung größerer Setzungen aus. In Auswertung entsprechender Erddruckmessungen, die in der Vergangenheit in Stuttgart und Dresden durchgeführt wurden, lassen sich die Angaben der neuen DIN 4085 für leichte Verdichtung ergänzen, wenn bestimmte Einschränkungen bei der Auswahl der Verdichtungsgeräte eingehalten werden. Earth pressure due to light compaction. The earth pressure acting on backfilled walls is increased by compaction. A light compaction suffices in many cases to prevent larger settlements. Earth pressure measurements were performed in the past in Stuttgart and Dresden. Based on these measurements, the specifications of the new DIN 4085 are complemented for light compaction. [source]

    Ein neues Verfahren zur Berechnung des räumlichen passiven Erddrucks vor Trägern

    BAUTECHNIK, Issue 7 2007
    Carsten Neuberg Dr.-Ing.
    In diesem Beitrag wird ein einfaches Berechnungsverfahren zur Bemessung horizontal belasteter, in den Untergrund eingebetteter Träger vorgestellt, das für baupraktische Aufgaben geeignet ist. Grundlage für die Herleitung sind die Ergebnisse von Messungen an Bauwerken, Modellversuchen und in besonderem Maße die Ergebnisse von numerischen Simulationen. Dazu wurde eine modifizierte Diskrete-Elemente-Methode (DEM) benutzt. Die Grundlagen für dieses Rechenverfahren sind in einem vorangegangenen Beitrag vorgestellt worden. A calculation method for the spatial passive earth pressure acting on girders. This paper presents a calculation method for vertical girders in cohesionsless soils. Measurements on buildings and model experiments are the basis. The Distinct Element Method (DEM) was extended and improved to enable the numerical simulation of load tests. Based on this knowledge, conditions not covered by experiments was simulated by means of the DEM. Accordingly, the test matrix could be extended. With the results of these simulations a new calculation method was derived. [source]

    Untersuchung zur Erddruckbeanspruchung von Winkelstützwänden

    BAUTECHNIK, Issue 12 2004
    Martin Achmus Univ.-Prof.
    Die Bemessung des vertikalen Schenkels von Winkelstützwänden ist gemäß derzeitiger deutscher Normung für erhöhten Erddruck, d. h. den Mittelwert aus aktivem Erddruck und Erdruhedruck, vorzunehmen. Dieser Ansatz liegt, wie im vorliegenden Aufsatz gezeigt wird, in vielen Fällen deutlich auf der sicheren Seite. Mittels einer numerischen Parameterstudie werden die wesentlichen Einflußfaktoren aufgezeigt. Auf der Grundlage der Ergebnisse wird ein Verfahren vorgeschlagen, das die genauere Festlegung der Erddrucklast unter Berücksichtigung der wesentlichen Einflußgrößen in einfacher Weise ermöglicht. Investigation on the earth pressure loading of L-shaped retaining walls. Due to current German regulations the structural design of the vertical wall stem of L-shaped retaining walls is based on the assumption of increased earth pressure loading, i.e. the average of active earth pressure and earth pressure at rest. In the presented paper it is shown that with this approach the resultant loading is in most cases overestimated. The influence of the most important parameters is investigated by a numerical model. Based on the results, a simple method for a more accurate estimation of the resultant loading is proposed. [source]

    Tragverhalten von teilweise vorgefertigten Stahlbetonwänden mit Ortbetonergänzung und integrierter Wärmedämmung

    BAUTECHNIK, Issue 11 2004
    Ralf Gastmeyer Dr.-Ing.
    Bei teilweise vorgefertigten Stahlbetonwänden mit Ortbetonergänzung und integrierter Wärmedämmung erfolgt die Verbindung des innen- und außenseitigen Betonquerschnitts meistens durch Gitterträger mit Diagonalen aus nichtrostendem Betonstahl. Die Gitterträger bewirken unter anderem eine schubweiche Kopplung der beiden Wandschalen, die bei der Weiterleitung von rechtwinklig zur Wandebene wirkenden Lasten (Wind oder Erddruck) und bei Temperaturänderung sowie unterschiedlichem Schwinden des innen- und außenseitigen Betonquerschnitts zum Tragen kommt. Nachfolgend werden die hieraus folgenden Beanspruchungen der äußeren Wandschale und der Gitterträger erläutert, die maßgebend für die Bemessung dieser Bauteile sind. Load carrying behaviour of partially precast concrete panels with additional site-cast concrete and integrated thermal insulation. For partially precast concrete panels with additional site-cast concrete and integrated thermal insulation, the connection between the interior and external wall layer currently is made by using stainless steel lattice girders. The lattice girders are leading to a flexible shear connection of both wall layers, which is acting under transversal loads (wind or earth pressure), under temperature changes and different shrinkage of the interior and external concrete cross section. Following the loads acting on the outer wall layer and on the lattice girders will be described, which are significant for dimensioning of these construction elements. [source]