摘要:

AbstractThe paper presents a solution for calculation of the surface uplift field of a semi‐infinite elastic solid embedded with a pressurized elliptical crack oriented at any angle, and at any depth. The results presented are those for a uniform pressure loading on the crack face, simulating a static pressurized hydraulic fracture, but the mathematical technique developed can be extended directly to non‐uniform normal loads or general shear loads in the form of a polynomial up to the third order. The result of a special case of the new solution, where the crack is penny shaped and parallel to the free surface, is compared with results from Sun's solution and from experiments which were designed and performed by the authors. The experiments involved pressurization of a penny‐shaped crack in a polyurethane material which is linear elastic under low stresses, and measurement of surface deformation by holographic interferometry and Fizeau interferometry. The correspondence between theory and experiment is exce

ISSN:0363-9061    

DOI:10.1002/nag.1610180502

出版商:John Wiley&Sons, Ltd    

年代:1994

数据来源: WILEY

摘要:

AbstractThe equations governing the dynamic behavior of saturated porous media as well as a finite element spatial discretization of these equations are summarized. A three‐parameter time integration scheme called the Hilber–Hughes–Taylor α‐method is used together with a predictor/multi‐corrector algorithm, instead of the widely used Newmark's method, to integrate the spatially discrete finite element equations. The new time integration scheme possess quadratic accuracy and desirable numerical damping characteristics. The proposed numerical solution and bounding surface plasticity theory to describe the constitutive behaviour of soil have been implemented as the computer code DYSAC2. Predictions made by DYSAC2 code are verified using dynamic centrifuge test results for a clay embankment. Importance of initial state of a soil on its dynamic behaviour is de

ISSN:0363-9061    

DOI:10.1002/nag.1610180503

出版商:John Wiley&Sons, Ltd    

年代:1994

数据来源: WILEY

摘要:

AbstractResults from five different computer models for structural deformation in jointed rock are compared for a problem involving stress‐wave loading of a lined circular tunnel in a jointed medium. The computer models include two discrete element codes, The Direct Interacting Block Systems (DIBS) and The Universal Distinct Element Code (UDEC), and three finite element codes, The Finite Element Code for Largely Explicit Calculation (FLEX), The Explicit Calculations of Interacting Bodies Under Rapid Loading Code (EXCALIBUR), and PRONTO. The finite element codes used either slidelines or joint elements to simulate the motion on joints.All codes had some difficulties with a sequence of preliminary problems solved to ‘shake down’ the computer codes. However, most of the shortcomings of each code were readily overcome. Results showed that three codes could obtain similar answers for tunnel closure, stress around the tunnel and slip on the j

ISSN:0363-9061    

DOI:10.1002/nag.1610180504

出版商:John Wiley&Sons, Ltd    

年代:1994

数据来源: WILEY

摘要:

AbstractConformal mapping techniques are used to obtain an exact solution for seepage flow below a hydraulic structure founded on permeable soil of infinite depth for a flat floor with an inclined cut‐off at the downstream end. Results are presented for different values of b/s and θ. The exit gradient decreases considerably along a distance beyond the floor end with an increase in cut‐off inclination. The maximum exit gradient decreases for θ = 10, 20 and 30° and starts increasing for θ = 45°. The uplift pressure decreases as θ increases. It is concluded that using an inclined cut‐off increases the factor of safety in design against uplift

ISSN:0363-9061    

DOI:10.1002/nag.1610180505

出版商:John Wiley&Sons, Ltd    

年代:1994

数据来源: WILEY

ISSN:0363-9061    

DOI:10.1002/nag.1610180506

出版商:John Wiley&Sons, Ltd    

年代:1994

数据来源: WILEY

ISSN:0363-9061    

DOI:10.1002/nag.1610180501

出版商:John Wiley&Sons, Ltd    

年代:1994

数据来源: WILEY