In the past 25 years great strides have been made in the area of static stability and deformation analysis. The widespread availability of microcomputers has brought about considerable change in the computational aspects of slope stability analysis. Analyses can be done much more thoroughly, and, from the point of view of mechanics, more accurately than was possible without computers. Still, engineers performing slope stability analyses must have more than a computer program. They must have a thorough mastery of soil mechanics and soil strength, a solid understanding of the computer programs they use, and the ability and patience to test and judge the results of their analyses to avoid mistakes and misuse. Realistic analyses of deformations of slopes and embankments were not possible until about 25 years ago. They are possible now mainly because the finite-element method has been developed and adapted to these applications. The principal requirement for achieving reasonably accurate and useful results fro...

State of the Art: Limit Equilibrium and Finite-Element Analysis of Slopes

Introduction and Overview External Loads Design of Gravity Flow Pipes Design of Pressure Pipes Buried Pipe Products

Buried Pipe Design

1. Site Investigation 2. Soil Classification 3. Rock Classification 4. Field Sampling and Testing 5. Soil Strength Parameters from Testing 6. Rock Strength Parameters from Testing 7. Soil Properties and the state of the Soil 8. Permeability and its influence 9. Rock Properties 10. Material and Testing Variability 11. Deformation Parameters 12. Earthworks 13. Subgrades and Pavements 14. Slopes 15. Terrain Assessment, Drainage and Erosion 16. Geosynthetics 17. File Specifications 18. Rock Mass Classification Systems 19. Earth Pressures 20. Retaining Walls 21. Soil Foundations 22. Rock Foundations 23. Movements 24. Appendix - Loading 25. References

Handbook of geotechnical investigation and design tables

Building damage due to excavation-induced ground movement is evaluated using a damage criterion based on the average state of strain in the distorting portion of the structure, and by considering the effect of building shear stiffness on the distortions imposed by the ground settlement profile. Physical model tests and numerical simulations, correlated with case studies of building distortion and damage, have been used to evaluate these relationships for masonry bearing wall structures. The distinct element method was used to numerically model each masonry unit as a block, with the contacts between blocks having the stiffness and strength characteristics of mortar. In-plane displacements at the corners of the wall sections permitted determination of the average state of strain, and the components of rigid body tilt, angular distortion, lateral strain at the base, and the contribution of bending strain to the lateral strain in the upper portion of the wall. The increase in angular distortion with increase in the ratio of ground/structure shear stiffness (decrease in building shear stiffness) was examined for both elastic and cracked building walls. Cracking significantly reduced effective wall stiffness making the wall more conformable to the ground settlement profile, which increased angular distortion, causing it to approach the distortion (change in ground slope) that would occur in the absence of the structure.

Estimation of building damage due to excavation-induced ground movements

Neural network based prediction of ground surface settlements due to tunnelling

Analytic models and field data are used to develop procedures to evaluate the tolerance of brick‐bearing‐wall and small frame structures to the ground displacements that develop during opencutting and tunneling. The role of horizontal and vertical ground displacements are discussed and the effects of grade beams, building orientation and building location relative to excavation are examined. Case studies of structures adjacent to opencuts and tunnels are used to verify procedures for estimating potential for structures adjacent to excavations to sustain damage.

Building Response to Excavation‐Induced Settlement

Finite element methods are being used more and more during design, in cases involving compacted soil-structure interaction. In general, it is not practical to conduct extensive tests to obtain the compacted soil properties required by the finite element methods during the design phase. Alternatively, if finite element approaches are used for developing design tables, soil properties representative of typical soil types and compaction specifications are required. To provide the needed design soil parameters for a wide variety of soil conditions, laboratory testing is carried out on three soils: a sand, a silt, and a clay. These soils are prepared at density states ranging from loose to 95% of the maximum from the standard compaction tests (American Society for Testing and Materials (ASTM) D698, American Association of State Highway and Transportation Officials (AASHTO) T-99). The tests used to obtain the soil parameters are triaxial compression, isotropic compression, and one-dimensional compression. A consistent set of soil design parameters are obtained by fitting test results to a hyperbolic soil model representing Young’s modulus and bulk modulus as functions of stress.

Marco D. Boscardin

Papers

Building Response to Excavation‐Induced Settlement

Hyperbolic parameters for compacted soils.