Engineering Commons^™

Failure Of Micaceous Waste Tailings Dam, W. F. Brumund

International Conference on Case Histories in Geotechnical Engineering

The paper describes the failure and reconstruction of an 80 ft. high, 8 acre tailings impoundment in Western North Carolina. The darn was constructed using the upstream method of construction. The coarse fraction of the tailings was used as embankment construction materials; these consisted of coarse to fine sands. The fine fraction tailings consisted of low density, relatively low plasticity, layered fine sands and fine sandy silts with frequent inter bedding of micaceous silty clays. Although a 20.0 ft. section of the darn failed, the fine saturated tailings did not liquefy but rather slumped into the breach. Reconstruction was complicated …

Lake Monona Causeway - Madison, Wisconsin, Usa, W. W. Warzyn, C. A. Stoll

International Conference on Case Histories in Geotechnical Engineering

In 1965 and 1966, a 3,500’ long, hydraulically-placed, highway embankment was constructed over the very soft lakebed deposits of Lake Monona. The compressible deposits, which ranged in thickness from 40’ to 80’, included marl, organic silt and silty clay. An incipient shear failure occurred near the end of the 1965 construction season, necessitating embankment design and construction modifications. Pertinent slope stability and settlement data are summarized, as are time dependent changes in in-situ subsoil parameters. Measured settlements, which currently range from 3’ to more than 12’, agree well with basic consolidation theory and engineering predictions formulated at project inception. General …

Open Pit Mine Rock Dump Geotechnical Evaluation, Z. M. Zovodni, J. D. Tygesen, S. C. Pereus

International Conference on Case Histories in Geotechnical Engineering

Open pit mining generally involves moving large quantities of waste rock to disposal areas which are usually located near the mine. This waste rock must be disposed of in a safe, economical, and environmentally acceptable manner. The stability of the waste dump depends to a great extent on the physical properties of the underlying foundation. Information must be obtained to define and assess the strength, consolidation, distribution, topographic and hydrogeologic properties for the foundation materials. Methods for obtaining estimates of the material properties include: laboratory and field testing, back analysis, and indirect estimates from other material properties. Mining operations in …

Peculiar Behaviour Of The Manicouagan 3 Dam's Core, O. Dascal

International Conference on Case Histories in Geotechnical Engineering

The presence of some horizontal or subhorizontal zones of weakness (cracks or decompressed layers) led to high pressure development in the downstream part of the relatively wide till core of Manic 3 dam. A short description of the investigation works to determine the location of the weakness zones and an analysis of the causes which produced these zones are presented in this paper.

Performance Of A Stone Column Supported Embankment, R. R. Goughnour, R. D. Barksdale

International Conference on Case Histories in Geotechnical Engineering

The proposed expansion of ramps connecting Interstate Route 664 with Interstate Route 64 at Hampton, Virginia involved numerous high embankments and bridge structures over marshlands. Potential problems of embankment stability and excessive long term, post construction settlements were further complicated by very strict environmental constraints on acceptable construction methods. The solution chosen was stabilization of the in situ soils by the installation of stone columns. A description is given of stone column design, construction, field embankment instrumentation, and embankment performance for the first two years of operation. Four theories for predicting settlements of stone column reinforced ground are briefly reviewed. …

Performance Of An Embankment On Peat, R. E. Olson

International Conference on Case Histories in Geotechnical Engineering

A widely held view is that rates of compression of peats are controlled by secondary effects and thus cannot be analyzed using primary consolidation theory. Data are presented here for the time rates of settlement of an embankment on peat. Theoretical analyses based on laboratory vertical and radial flow consolidation tests, and utilizing a finite difference scheme, indicated that the soil had undergone a degree of mass flow and was disturbed during or before jetting of sand drains, but that the field settlements could be predicted rationally using primary consolidation theory.

Performance Of Trial Embankment On Soft Clay, T. Shibata, H. Sekiguchi

International Conference on Case Histories in Geotechnical Engineering

This paper is concerned with the interpretation of the observed and predicted performances of a full-scale trial embankment, which was constructed for the design purposes regarding a new bypass road to be constructed over soft clay adjacent to existing structures. The prediction based on the finite element analyses and the determination of soil parameters are briefly outlined. The results of comparison show adequate agreement between the predicted and observed field time-dependent deformation behavior throughout the entire loading history. However, if the predictions from the present FE-analyses are made by using the soil parameters measured in the laboratory, a correction factor …

Powerhouse Slope Behavior, Fort Peck Dam, Montana, J. V. Hamel, G. S. Spencer

International Conference on Case Histories in Geotechnical Engineering

Landslides occurred in the Bearpaw shale slope adjacent to the powerhouses at Fort Peck Dam in the geologic past. Excavation of the slope toe for construction of reservoir outlet works in 1934 initiated progressive sliding of colluvium which continued to 1974. The active slide area had an average movement rate of 4 ft/yr from 1944-1945 and average movement rates of 1-2 ft/yr from 1953-1971. These movements caused no distress to the powerhouses or other facilities. In 1974, the slope was stabilized by excavating 1.6 x 106 cu. yd. of material, resulting in a 1 on 6 overall slope. A field …

Slide Stabilization With Gravel Trenches, E. G. Wardlaw, L. A. Cooley, A. E. Templeton, R. L. Fleming Jr.

International Conference on Case Histories in Geotechnical Engineering

A different method of slide stabilization using gravel trenches is described. The design, construction, and performance monitoring of the gravel trenches are discussed together with a history of the slide, description of the soils, and mechanism of failure. The applications and limitations of this method of slide stabilization are also evaluated.

The Delayed Failure Of A Large Cutting In Hong Kong, R. R. Hudson, S. R. Hencher

International Conference on Case Histories in Geotechnical Engineering

A large cutting in decomposed granite failed after five days of dry weather following an extremely intense rainstorm in August 1982. The history of the slope and surrounding area is described and three theories that might explain the delayed nature of the failure are proposed.

The Failure Of A Cut Slope On The Tuen Mun Road In Hong Kong, S. R. Hencher, R. P. Martin

International Conference on Case Histories in Geotechnical Engineering

The investigation and analysis of two landslides in a recently-constructed cut slope in weathered granite are described in detail. The failures are attributed partly to complex geological conditions which caused a perched water table to develop in the major scar. Adverse jointing contributed to the minor failure. The original site investigation was not sufficiently detailed to identify the important geological and hydrogeological aspects of the site. Conclusions are drawn with respect to the usefulness of back analysis for identifying failure mechanisms.

The Foundation Of The Right Bank In Wadi-Zarat Dam, M. A. Benltayf, M. Atalla, K. Rabah

International Conference on Case Histories in Geotechnical Engineering

The geotechnical engineering characteristics of a calcareous crust formation are evaluated in order to determine the feasibility of its stability under the right bank of Wadi Zarat Dam. The crust is a rock similar, extremely heterogeneous, material with location of collapsing susceptibility when saturated. The formation is caverned and locally very permeable and can present a risk of losing the reservoir water, dissolution, settlement, and piping. In this case study, several alternatives to treat the crust formation are presented, discussed, and compared. Rational justifications for the adopted solution are given and the predicted performance during operation of the dam is …

Assessment Of Seismic Stability Of Earth Dams By Comparative Methods, Rodney J. Huang, Marshall L. Silver

International Conference on Case Histories in Geotechnical Engineering

Seismic stability of embankment dams and their foundations has been a major concern in recent years because of notable incidents such as the behavior of the Lower San Fernando dam in the San Fernando Earthquake. Sophisticated and involved analytical methods have been developed to study the behavior of dams in earthquakes. Predicted seismic behavior agrees well with measured seismic behavior in the few case histories that exist of seismically induced distress in dams. However, for many dams, the level of information or effort required for a complete sophisticated seismic analysis is not warranted. For such cases it is possible to …

Earthquake Damages To Earth Dams And Levees In Relation To Soil Liquefaction And Weakness In Soft Clays, W. S. Wang

International Conference on Case Histories in Geotechnical Engineering

In this paper, a number of case histories of typical earthquakes dams and levees which have been damaged by earthquakes occurred in past two decades in China are reported in some details along with data obtained from field and laboratory investigations as well as some analytical results. These damages are mainly due to liquefaction of saturated cohesionless or less cohesive soils and slippage in weak soft clays. It is concluded that, in order to avoid severe earthquake damages, earth dams and levees should be compacted to dense state and any liquefiable soils and weak soft clays in foundations should be …

General Report For Theme Five Case Histories In Geotechnical Earthquake Engineering, Gonzalo Castro

International Conference on Case Histories in Geotechnical Engineering

No abstract provided.

Liquefaction Of A Soil Deposit During An Earthquake, Shamsher Prakash, M. K. Gupta

International Conference on Case Histories in Geotechnical Engineering

Large number of cases have been rep or ted where liquefaction has occurred during the earthquake, but only in a few cases, soil report in the zones of liquefaction are available. A wide spread damage because of liquefaction of soil deposit was observed during tile Niigata Earthquake of 1964 in Japan. A very systematic study on soil exploration in the zone of liquefaction was carried out and is well reported. Two sites were selected for the analysis from Niigata in the same area (i) where heavy damage occurred (ii) where no damage occurred. A case study was made using two …

Liquefaction Potential Evaluation For Arcadia Dam, J. R. Wagner

International Conference on Case Histories in Geotechnical Engineering

The paper presents the studies performed as part of the liquefaction potential evaluation for Arcadia Dam. The evaluation was performed by the Tulsa District, Corps of Engineers, using a modification of the "Simplified Procedure" developed by H. B. Seed. A discussion of the various decisions, judgements and procedures used to adapt the required studies to the site specific conditions is presented along with a description of drilling, sampling, sample handling, and laboratory testing. The most significant finding from the evaluation is that a useful relationship exists between standard penetration test (SPT) blow count values, laboratory cyclic shear strength and soil …

Liquefaction Potential Of Silty Sand Site, H. Dezfulian, N. D. Marachi

International Conference on Case Histories in Geotechnical Engineering

Dynamic properties of subsurface soils at the site of a proposed nuclear power plant were determined through extensive field and laboratory tests. The liquefaction potential of the granular soils underlying the site were obtained by using field data obtained from both standard penetration resistance and cone penetration tests as well as from laboratory data obtained from cyclic triaxial compression tests. The analyses showed that comparable factors of safety may be obtained from both field and laboratory test data.

Liquefaction Risk Evaluation During Earthquakes, Qiao Taiping, Wang Chenchun, Weng Lunian, Liu Huishan

International Conference on Case Histories in Geotechnical Engineering

A simplified method is herein presented to evaluate liquefaction risk, where we modified the form of liquefaction potential index suggested by Iwasaki, Tokida and others (1980, 1982). Based upon the investigations of structure damage induced by soil liquefaction during Tangshan earthquake, four categories for evaluating liquefaction risk and the principles of engineering treatment are proposed. Several typical liquefaction sites are analyzed by this method.

Research On The Permeability And Earthquake Damage Of An Earth Dam Foundation, Zhi-Jie Zhu, Wen-Kai Liu

International Conference on Case Histories in Geotechnical Engineering

The experiences on geological investigation, permeability test, prediction of seepage failure patterns and the earthquake damage of an earth dam foundation are presented in this paper. Basing on the monitoring data and seismic records observed from the seismic station on the dam, the prediction of reservoir induced earthquake and possibility of liquefaction are analysed.

A Case Study On Decreasing Vibration Of Machine Foundations And Structures, Xikang Wang

International Conference on Case Histories in Geotechnical Engineering

Foundations under 3 compressors rested on a clay base. With the secondary exciting frequency falling into resonance region, the vibration velocity of foundations reached 8.96 mm/s exceeding the permissible limit. It was reduced to 4.0 mm/s through the use of combined foundation, thus ensuring normal production.

Behavior Of Compressor Foundation – Predictions And Observations, Shamsher Prakash, Vijay K. Puri

International Conference on Case Histories in Geotechnical Engineering

In a Compressor foundation undergoing excessive vibrations, its amplitudes at operating frequency and natural frequency in free vibrations were monitored. Also in-situ dynamic properties were determined to check design and predict its response. Since the soil constants are strain depondent, two sets of computations were done (1) from the known soil constants and permissible amplitudes and (2) from the known soil constants and the observed amplitudes. The soil constants were corrected for confining pressure and relative density of the non-cohesive soil also. Both weightless spring theory (Barkans’ Method) and elastic half space theory were used in predicting the response. A …

Geotechnical Problems In A Bridge Over Corinth Canal, S. G. Christoulas, N. A. Kalteziotis, G. K. Tsiambaos

International Conference on Case Histories in Geotechnical Engineering

The railroad bridge of Corinth Canal was founded in a stable tectonic block (horst) consisting of neogene marly limestones, marls and sands. After the last strong earthquake of 24th February 1981 an extension of existed subvertical joints, directed E-W, was observed close to the northern bridge abutment. A geotechnical study was carried out for the detection of the causes which created these phenomena and for the design of probable reinforcing measures. From the results of site investigations and laboratory tests and after considering the slope stability, it was concluded that the only risk for the abutment is the progressive change …

Pittsburgh's Mt. Lebanon Tunnels- Case History, G. L. Butler, B. P. Cavan, F. K. Mussger, G. W. Rhodes, H. T. Whitney

International Conference on Case Histories in Geotechnical Engineering

Discussions of basic design philosophy and comparison of alternative contract bid options are presented. Also discussed are descriptions of field monitoring activities with respect to the construction methods, ground response, installation of materials and their performance. Finally, conclusions are reached relative to the NATM philosophy as applied to this project and its place as a design process within the context of United States underground construction practice.

Shale Pit Slopes - A Case History, D. H. Shields

International Conference on Case Histories in Geotechnical Engineering

The preliminary design for 180 metre high open pit mine slopes in shale is described. Given the complex geology and material properties, the first choice would have been to use reliability theory. The state-of-the-art of probabilistic methods in geotechnical engineering precludes this, and a deterministic approach to design was resorted to instead.

Squeezing Problems In Indian Tunnels, J. L. Jethwa, A. K. Dube, B. Singh, Bhawani Singh

International Conference on Case Histories in Geotechnical Engineering

Case histories of three Indian tunnels indicate that squeezing conditions are created due to plastic flow of rock masses under the influence of high cover pressures. These examples emphasize that a tunnel experiencing squeezing conditions must be allowed to deform to optimize support costs and avoid delays. Allowance for desirable tunnel deformations must, therefore, be made while planning the size of excavation.

Field data has shown that a flexible support system of compressible backfill and steel ribs may be used as an alternative to shotcrete support which is unpractical in Indian tunnels excavated largely by conventional methods. Instrumentation indicates that …

Stillwater Tunnel, Central Utah Project, Utah - Case History, R. S. Sinha, K. D. Schoeman

International Conference on Case Histories in Geotechnical Engineering

Described is the case history of Stillwater Tunnel highlighting the aspects of design, construction, instrumentation, and contracting procedures, which on September 14, 1983, culminated in the successful holethrough for this 8.03-mile (12.92-km) long water conveyance tunnel. The case study demonstrates that for a successful project it is essential to carefully select a ·compatible excavation system and a contractor who has the incentive to complete the project within the resources of available time and budget. The study illustrates the weaknesses in the current state of the technology for design and construction of deep and long tunnels and urges an improvement of …

The Stability Of Underground Power Chambers In The Brittle Rock, Weishen Zhu, Kejun Wang, Guangzhong Peng

International Conference on Case Histories in Geotechnical Engineering

The statistical analysis has been executed for the phenomenon of disk cores in the dam site, which has been compared with the condition of high geostresses. The mechanism to form disk cores and the stress state and energy distribution around underground power houses have been analysed with FEM. In addition, the modelling test to investigate the stability of underground house with block material is introduced. Finally some practical conclusions are proposed.

A New Method Of Stabilization Of Soft Soils, M. A. Aziz

International Conference on Case Histories in Geotechnical Engineering

A new method of stabilization of soft soils using split-bamboo poles filled up with coconut coir wicks has been described. The results of the field tests of this new method on an actual construction site have been critically analysed and discussed.

Construction Of The Key Lake Tailings Facility, R. B. Knight, J. P. Haile

International Conference on Case Histories in Geotechnical Engineering

Construction of the Tailings Storage Facility for the Key Lake Project a major uranium mine in northern Saskatchewan, Canada, was completed in June, 1983. Principal design features of the tailings facility are an underseal and underdrainage system over the entire area, systematic deposition of the tailings in thin layers using the sub-aerial technique, and continuous removal and recycling of all surface water and underdrainage outflows to the mill for treatment. These features are designed to achieve a consolidated, drained tailings deposit suitable for immediate decommissioning QD completion of milling, and with a minimal potential of long term seepage. The design …