Analytic Modeling of Rock-Structure Interaction
Jeremy Isenberg
U.S. Bureau of Mines
R-7215-2299
August 1972
A number of recent advances in finite element theory and computer technology are combined into a computer program for analysing structures and cavities in rock. The program applies to general three-dimensional forms, considers non-linear material properties including joints, anisotropic and time-dependent material properties, gravity loading and sequence of construction or excavator. Example problems, demonstrating the ability of the program to reproduce ideal situations having closed-form, analytic solutions are solved.
Blasting for Rock Excavations
U.S. Army Corps of Engineers
EM 1110-2-3800
30 October 2018
This manual describes theory, concepts, and procedures surrounding rock excavation through the use of blasting agents and methods for use on Civil Works and Military Construction projects. It is intended to provide guidance to U.S. Army Corps of Engineers personnel (USACE) involved in the planning, design, monitoring, or implementation of blasting programs for rock excavation.
The scope of this manual is limited to the use of blasting agents and methods for the purposes of rock excavation. While this may involve the removal of overburden, blasting near structures, and other specialty methods, this manual does not cover demolition of structures, or the use of explosives for ordinance. It is intended to acquaint the practitioner with the materials, tools, and methods for executing blasting programs for rock excavation. It is also intended as a guide for engineers and geologists designing excavation programs and for construction monitoring of those programs.
There are many tools and techniques available for rock excavation, but few are as economical as the use of explosives. Rock blasting is effective for work as small as boulder removal (which use only very small amounts of explosives), to large scale excavations for mining, dam foundations, building foundations, lock construction, tunneling, and roadway building. The U.S. Geological Survey reports that, in 2012, total annual explosives consumption in the United States was 3.38 million metric tons and that explosives are used in “…virtually every segment of the manufacturing and major construction industry” (Apodaca 2012). Even though blasting materials are potentially dangerous and must always be handled with respect, caution, and great care, these blasting agents are vital part of the engineering toolbox.
Evaluating the Stability of Existing Massive Concrete Gravity Structures Founded on Rock
Robert M. Ebeling, Michael E. Pace and Ernest E. Morrison, Jr.
U.S. Army Corps of Engineers, Waterways Experiment Station
Technical Report REMR-CS-54
July 1997
The U.S. Army Corps of Engineers is responsible for designing and maintaining a large number of navigation and flood-control structures. Many of the older massive concrete gravity hydraulic structures are being examined to determine if rehabilitation is required to meet stability criteria. The procedures currently used for evaluating the safety of existing massive hydraulic structures are the conventional equilibrium methods. These methods are the same general methods used in the design of these structures. These engineering procedures have been used for decades by civil engineers to design new hydraulic structures and analyze existing structures. Because the conditions of equilibrium are insufficient for a complete analysis of all aspects of structure-foundation interaction involved in the stability and performance of these structures (soil- structure-foundation interaction in the case of earth-retaining structures), these conventional equilibrium methods necessarily involve assumptions regarding aspects of the loading forces and the resisting forces that act on the hydraulic structures.
Although the conditions and assumptions employed in the conventional equilibrium-based design methods are generally accepted as providing reasonable engineering procedures, and although there have been few reported failures of hydraulic structures designed using these procedures, there is some uncertainty concerning their accuracy. Differences between actual field performance and calculations from conventional analysis have been noted for some existing hydraulic structures. Conventional design methods were developed based largely on classical limit equilibrium analysis without regard to deformation-related concepts. Today, analytical tools such as the finite element method (FEM) are available that consider the manner in which the loads and resistance are developed as a function of the stiffnesses of the foundation rock, the structure- foundation interface, and rock joints within the foundation. These analytical tools provide a means to evaluate the conventional equilibrium-based design methods used to evaluate the safety of existing hydraulic structures. Specifically, these advanced analytical tools are used to identify and investigate key assumptions used in safety calculations from the conventional analysis.
The research investigation described in this report was undertaken to study the behavior of gravity hydraulic structures using the FEM of analysis and to compare the results of the finite element (FE) analysis.
Literature Review of Rock Properties for Analysis of Navigation Structures Founded on Rock
Carl Philip Benson
Virginia Polytechnic Institute
October 1986
A review of behavioural rock properties used for input to the finite element method are summarized. Rock properties presented in the literature were primarily obtained from laboratory specimens. Methods to determine applicable field properties via testing , calculations and empirical correlations are included. Suggested behavioural properties of the structural concrete-to-rock interface are proposed. Specific property values, resulting from the literature review, are presented as input for a finite element parametric evaluation of navigation structures.
Methods of Evaluating the Stability and Safety of Gravity Earth-Retaining Structures Founded on Rock, Phase 2 Study
Ebeling, R. M., Duncan, J. M. and Clough, G. W.
US Army Corps of Engineers
Technical Report ITL-90-7
October 1990
The objective of this study was to investigate the accuracy of the procedures employed in the conventional equilibrium method of analysis of gravity earth-retaining structures founded on rock using finite element method of analysis. This study was initiated when a number of existing large retaining structures at various navigation lock sites in the United States that showed no signs of instability or substandard performance failed to meet the criteria currently used for design of new structures.
The results of the following load analyses show that when the loss of contact along the base of a wall is modeled in the finite element analysis, the calculated values of effective base contact area and maximum contact pressure are somewhat larger than those calculated using conventional equilibrium analyses. The values of the mobilized base friction angle calculated by both methods are in precise agreement.
Comparisons between the results of backfill placement analyses using he finite element method and the conventional equilibrium analyses indicate that conventional analyses are very conservative. The finite element analyses indicate that the backfill exerts downward shear loads on the backs of retaining walls. These shear forces have a very important stabilizing effect on the walls. Expressed in terms of a vertical shear stress coefficient (
Another important factor not considered in the conventional equilibrium method is that the displacements of the wall have a significant influence on the distribution of both the stabilizing and destabilizing forces exerted on the wall. In general, as the wall moves away from the backfill, the lateral forces exerted on the front of the wall by the toe fill increase.
Rock Blasting and Overbreak Control
FHWA-HI-92-001
December 1991
This handbook is specifically designed as a guide to highway engineers and blasting practitioners working with highway applications. It was used as a handbook for the FHWA courses of the above title. The handbook is a basic review of explosives and their characteristics, along with explosive selection criteria. Initiations and timing effects as well as patterns are also discussed.
A simple step by step procedure is outlined to help the engineer review blasting submittals in a systematic fashion. Air blast and ground vibration are discussed along with methods for evaluation and control. Several solved examples are presented in a manner to simplify the necessary calculations with step by step procedures given where appropriate.
Rock Engineering
We also offer the companion software RocLab for Windows 95/98/Me/NT/XP, which includes online help and instructions.
Click here to download RocLab.
Evert Hoek
A complete treatment on the subject. Topics include the following:
- Development of Rock Engineering
- When is a rock engineering design acceptable
- Rock mass classification
- Shear strength of discontinuities
- Structurally controlled instability in tunnels
- The Rio Grande project–Argentina
- A slope stability problem in Hong Kong
- Factor of safety and probability of failure
- Analysis of rock fall hazards
- In situ and induced stresses
- Rock mass properties
- Tunnels in weak rock
- Large powerhouse caverns in weak rock
- Rock bolts and cables
- Shotcrete support
- Blasting damage in rock
- References
Rock Foundations
EM 1110-1-2908
30 November 1994
This manual is intended to provide, where possible, a guided approach for the design of rock foundations. The concept of guided design provides for a stepped procedure for solving engineering problems that requires solution by decision making and judgement. Any design which involves rock masses requires a decision making process in which information must be obtained, considered, and reconciled before decisions and judgements can be made and supported. As such, the manual provides a stepped procedure for planning, collecting, and characterizing the information required to make intelligent decisions and value judgements concerning subsurface conditions, properties, and behaviour. A fully coordinated team of geotechnical and structural engineers and engineering geologists are required to insure that rock foundation conditions and design are properly integrated into the overall design of the structure and that the completed final design of the structure is safe, efficient, and economical. Foundation characterization and design work should be guided by appropriate principles of rock mechanics.
Rockfall Hazard Rating System – Participants’ Manual
Lawrence A. Pierson, C.E.G. and Robert Van Vickle, R.P.G.
FHWA-SA-93-057
August 1993
Development of the Rockfall Hazard Rating System (RHRS) is complete. The system has been fully tested and implemented by the Oregon Department of Transportation. The RHRS is a process used in the management of rockfall sites adjacent to highways. The system is proactive by design, providing a rational way to make informed decisions on where and how to spend construction funds in order to reduce the risks associated with rockfall.
This Participant’s Manual documents the components of the RHRS, the steps an agency should follow to implement the system, and discusses the level of commitment required. The benefits of implementation and the limitations of the system are also described. The manual serves as both a field guide and as a desk top reference for those who perform the slope ratings and those who use the resulting database in establishing rockfall remediation designs and construction priorities.
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