Geotechnical Engineering Commons^™

Experimental Determination Of Stresses On A Model Silo, V. Kamgueu

International Conference on Case Histories in Geotechnical Engineering

In this paper we present some results obtained from a cylindrical model silo designed by using the well known Janssen asymptotic expression of bin pressure. Two kinds of tests have been conducted.

- one by varying the outlet diameter, (d)

- the other by varying the hopper slope, Ɵ

All these variation are done to obtain man-flow in the model. The electric responses of the sbain gages give some information on the deformations of the transition zone. Close to the hopper and reveal the existence of a peak stress responsible of the destruction of many industrial silos cited in the …

Case History On Prevention Of The Landslide At Luoyiqi By Means Of Rigid Frame Retaining Structure, Xu Fenghe, Wang Jinsheng

International Conference on Case Histories in Geotechnical Engineering

This paper presents a new special type of retaining structure which prevents the large-scale landslide. It is named the rigid frame retaining structure. The author in this paper proposed a new computation method, i.e., analysis of the rigid frame within elastic foundation. The new formulations have been performed according to E. Ninkler's theory and the difference principle and with the help of fundamental knowledge of strength of material and matrix algebra. The descriptions of the design and construction of the rigid frame retaining structure were given.

Predicted And Observed Lateral Deformations Of Anchored Retaining Walls, Tj. Kooistra, F. L. Beringen

International Conference on Case Histories in Geotechnical Engineering

Backanalysis of deflection measurements for a diaphragm and a sheet pile wall in Holland has shown that the results are mostly sensitive to the profile of coefficients of subgrade reaction. A sensitivity study performed to compare the wall deflections calculated with the Menard and Terzaghi theory shows that the moduli according to Menard produces best agreement. The analyses were carried out using a one dimensional finite element programme. It is shown that displacement measurements obtained from easy to perform inclinometer surveys.

Field Experience On Corrugated Metal Culverts, P. Habib, N. T. Long, G. Legeay, A. Millan, L. Baude

International Conference on Case Histories in Geotechnical Engineering

The behaviour of buried structures in earth embankments is related to the stiffness properties of the composite system comprising both the buried structure and the surrounding soil taken as a basic structural unit responding to loading imposed on the system. A field experience on corrugated metal culverts equipped with contractable seams has been carried out in order to verify the transfer of load to or away from the buried structure as a result of the difference in stiffness properties of the structure, with its adjacent encompassing material, and the surrounding expanse of soil.

Braced Cofferdam To Improve Spillway Stability During Rehabilitation, Rodney M. Wong, James T. Passage, Sami S. Naami

International Conference on Case Histories in Geotechnical Engineering

Dewatering of scour pools at the toe of existing spillways can significantly increase forces on such structures and reduce their overall stability below acceptable levels. Such dewatering may be required however to undertake needed repairs or to construct a stilling basin. Use of a braced cofferdam permits the necessary dewatering while at the same time temporarily improving the stability of the spillway. This is accomplished by mobilizing earth pressures and tailwater pressures through the braces to restrain the spillway against sliding.

The Pathology Of Metal Culverts, N. T. Long, A. L. Millan

International Conference on Case Histories in Geotechnical Engineering

Metal culverts are robust structures, but the very large number built every year entails, statistically, a rather high level of pathology. The various aspects of this pathology are analyzed below, first from a general point of view and then through an examination of three particularly instructive cases.

Field Behavior Of Retained Earth Structure, Z. Al-Yassin, C. K. Shen

International Conference on Case Histories in Geotechnical Engineering

This paper describes a case study of a Retained Earth system constructed for the on- and off-ramps of a grade separation structure in Hayward, California. Field strain gage readings of reinforcing meshes were recorded at two instrumented sites. The results were closely examined and analyzed to assess the current design procedure. Based upon the information gathered, it was concluded that the field performance behavior of the system seems to justify the current general design procedure. However, it was also noted that the design of earth reinforced structures is complicated due to the interaction between the reinforcing elements and the surrounding …

Failure Of An Anchored Sheetpile Bulkhead, D. P. Lagatta, D. R. Shields

International Conference on Case Histories in Geotechnical Engineering

An anchored steel sheetpile bulkhead was constructed in soft organic silt and clay. The bulkhead failed when the anchors ruptured during dredging in front of the bulkhead. The construction and failure of the bulkhead are described. Analyses were performed to investigate the cause of the failure. The major factors which contributed to the failure were: 1) failure to design for the lowest tide condition, 2) use of design soil strengths which were too high, 3) prestressing of the anchor system which resulted in increased anchor loading due to soil arching, and 4) bending stresses induced in the anchors by settlement …

Failure Of A Small Gravity Dam And The Repair, David F. Mccarthy

International Conference on Case Histories in Geotechnical Engineering

Late in the summer of 1980, the dam for Snowbird Lake in Forestport, New York, U.S.A., experienced a serious foundation leak made evident by a suddenly erupting geyser near the downstream toe. Subsequent investigation indicated that a severe piping condition had occurred in the soil foundation. Some degree of erosion had effected the foundation earth for more than half of the dam length. Repairs were performed after dewatering the dam work area. The original dam was retained but provided with a new concrete foundation which included a constructed underdrain. A clay blanket was installed on the dam's upstream side to …

Damage And Remedial Measures For Buildings On Hill Slopes, Swami Saran, Gopal Ranjan, Bhawani Singh, A. S. R. Rao

International Conference on Case Histories in Geotechnical Engineering

The paper deals with details of geotechnical investigations carried out for evaluating the reasons of damage to the buildings resting on hill slopes in northern region of India and also to evaluate the soil parameters for designing retaining walls and other remedial measures for preventing further damage to structures. Three causes of failure were identified namely (i) instability of slopes, (ii) improper design of retaining walls and (iii) differential settlement of structures. Shear strength parameters of the soil mass required for the analysis of slope stability and stability of retaining wall sections have been chosen based on three methods of …

An Embankment On Soft Clays With Sand Drains Numerical Characterization Of The Parameters From In-Situ Measurements, A. Cancelli, A. Cividini

International Conference on Case Histories in Geotechnical Engineering

The deformation parameters of a soft lacustrine deposit, with vertical sand drains, are evaluated by means of field measurements obtained during and after the construction of a railway embankment. The geotechnical system, modelled as linearly elastic and in plane strain, is analyzed by means of the finite element method and the estimation problem is solved adopting a Bayesian approach. The experimental data, the "a priori" estimation of the parameters and their uncertainties are considered in the back-analysis. The results provide the "optimal" values of the parameters, a measure of their uncertainties and, consequently, an index of the effectiveness of the …

Baldwin Hills Reservoir Failure, G. A. Leonards

International Conference on Case Histories in Geotechnical Engineering

No abstract provided.

Behaviour Of Ramganga Dams, Bhagwat V. K. Lavania

International Conference on Case Histories in Geotechnical Engineering

Two earth and boulder fill dams of height 127.6 m and 72.2 m are major structures of Ramganga River Project. Their foundation rocks are alternations of clayshale and sandrock of Middle Siwaliks. Both have thick core consisting of central zone of crushed clayshale encased by crushed sandrock zones. The clayshale and sandrock available from spillway excavations, just adjacent to these dams, were utilized as dam fill. No major problem except that of seepage control in cut off trench excavation and compaction near abutments, was encountered during construction. Both the dams are well instrumented. Their construction was completed in 1974-75 and …

Collapsible Soils Chashma Right Bank Canal, Izharul Haq

International Conference on Case Histories in Geotechnical Engineering

In 1979-81 a stretch of 10 miles of Chashma Right Bank Canal was excavated and double layer brick tile lining was done. The lining was cured by flooding it with water through open drains made on either berm of lining. A couple of months after the completion of the lining, horizontal cracks were observed on either bank. Field density, moisture measurements, Soil classification and double Oedometer tests were performed. In situ water pending tests were also conducted. The observations and the test results revealed that the cracks were the consequence of collapse of silty low density soil due to saturation. …

Controlled Breaching Of A Full Scale Clay Flood Bank, A. Marsland

International Conference on Case Histories in Geotechnical Engineering

A mature clay flood bank was subjected to seepage and overtopping tests. Tides were simulated by pumping water into a sheet pile coffer dam enclosing the river ward side of a 18 m length of bank. Measurements were made of the seepage, the pore water pressure in the bank, and movements of the bank. Tides of increasing height were applied until finally the water started to flow over the top of the bank. Within a few minutes of the commencement of shallow overtopping a slip developed in the desiccated clay within the landward slope of the bank. This was rapidly …

Deep Seated Base Failure And Reconstruction Work, M. Fukuoka

International Conference on Case Histories in Geotechnical Engineering

As an embankment was constructed on thick soft clay ground, a deep seated failure took place. A large horizontal and vertical deformation was observed along the suspected sliding surface of the deep seated failure, when sand compaction piles were driven into the foundation for the purpose of soil improvement. After the soil improvement, an embankment was going to be reconstructed, but a sliding along the old sliding surface was feared. Since the amount of lateral movement was small, effectiveness of the sand compaction piles was ascertained. This paper presents a case record of this work.

Design And Performance Of Horizontal Drains, J. H. Kleppe, G. M. Denby

International Conference on Case Histories in Geotechnical Engineering

The paper presents a comparison of field and analytical data regarding the performance of horizontal drains installed to stabilize a landslide. Results of the comparison provide generalized guidelines with which to design drain spacing, length and position. The most significant conclusions are, firstly, that horizontal drains were able to successfully depressurize a silty fine sand with up to 60% silt; secondly, that the ultimate drawdown that can be achieved by slotted horizontal drains in fine-grained soils is controlled primarily by the elevation of the drain; and thirdly; that the design drain spacing is dependent primarily on the initial drawdown response …

Earth Dams At Nuclear Power Plants, R. Pichumani, D. C. Gupta, L. W. Heller

International Conference on Case Histories in Geotechnical Engineering

Many of the nuclear power plants under operation or construction use earth dams to impound cooling water for the safe shutdown of the plants in an emergency. The U.S. Nuclear Regulatory Commission reviews the licensee s design and analysis of the dams associated with the nuclear plants. An example of an earth dam includ1ng its unusual design features such as a high phreatic surface and a zoned blanket dra1n, safety analyses, and performance monitoring is given. Where well established procedures have been properly implemented during design, analysis, and construction and when supported by field monitoring and periodic inspections, the dams …

Efficacy Of Grout Curtain At Ramganga Dam, M. C. Goel, B. N. Sharma

International Conference on Case Histories in Geotechnical Engineering

The analysis of foundation piezometer records at main dam and saddle dam of Ramganga Project, has indicated that the single row grout curtain at main dam, is ineffective so far as the hydrostatic pressure reduction in foundation is concerned, whereas under similar conditions, upstream impervious blanket at saddle dam, is more effective in pressure reduction. Experimental test results by electrical analogy technique using graphite paper, has indicated that in case of Ramganga main dam, the total net pressure reduction for fully effective grout curtain would have been only 25%. The design curve for efficiency versus different openings in grout curtain …

Evolution Of Design And Construction Of Lornex L-L Tailings Dam, M. D. (Dal) Scott, Robert C. Lo

International Conference on Case Histories in Geotechnical Engineering

The evolution of the Lornex tailings disposal facility, in particular the Lower L-L Dam, throughout the design and construction phases is presented with the emphasis on how economic considerations have dictated this process. Major episodes described here include: the early conversion to an energy efficient t wo-dam storage scheme, the reduction of the size of the L-L Starter Dam, the buttressing of the Starter Dam in an area involving soft foundations, and the development of hydraulic means to use cycloned tailings sand for annual raising of the L-L Dam. Extensive instrumentation was installed to monitor the performance of the L-L …

Failure Of An Embankment On Soft Clay, M. K. Yegian, Hugo Perez Lasalvia

International Conference on Case Histories in Geotechnical Engineering

The failure of an embankment during its construction on soft clay foundation is investigated. Field and laboratory data are used in conventional slope stability analyses to explain the cause of the failure and to evaluate the in-situ undrained shear strength of the clay which was later used in the design of the replacement dike. The results indicate that whereas the stiff embankment having a well compacted core was initially stable on the soft clay, subsequent cracking of the core due to undrained deformations reduced the shearing resistance of the dike thus, initiating the failure. The dike was eventually reconstructed in …

Failure Slope In Clay Shales In Aratu Bay - Brazil, R. B. Guimarães

International Conference on Case Histories in Geotechnical Engineering

Three slides at the same slope, 35m high, on clay shale are analysed. Geological and geotechnical features are shown. Back analysis from the last two slips and sensitivity analysis were done. Good predictions and mistakes are shown.

General Report For The Theme Three – Case Histories In Dams, Embankments And Slopes, D. E. Kleiner

International Conference on Case Histories in Geotechnical Engineering

Of the approximately forty papers submitted for sessions 3A and 3B on Case Histories in Dams, Embankments and Slopes, eighteen specifically discuss dams, foundations for dams or tailings dams. Table 1 presents a capsule summary of those papers that discuss dams and their foundations. Table 2 is a similar capsule summary of the five papers that discuss performance, design and/or construction of tailings dams or spoil piles. This general report summarizes and comments on the papers listed in Tables 1 and 2, presents several abbreviated case histories that parallel those presented in the papers, comments on several points not covered …

Grand Coulee Riverbank Stabilization – Case History Of The Design Of Remedial Measures, J. Lawrence Von Thun

International Conference on Case Histories in Geotechnical Engineering

Planned peaking operations at Grand Coulee Dam will cause river fluctuations of up to 1 feet daily for the authorized plant and up to 38 feet daily for a proposed plant expansion. Treatment of the historically unstable riverbanks was required to offset the destabilizing effect of the peaking operations. Consideration of the geologic history of the bank materials, estimation of future pore pressure conditions, formulation of the stabilization criteria, and the success in reducing pore pressure levels in varved clays in the bank were some of the important aspects of this project.

Performances Of Some Embankment Dams In India, T. Ramamurthy

International Conference on Case Histories in Geotechnical Engineering

The performance in terms of pore pressure and deformation of five earth and earth-rock-fill dams is briefly presented. These darns are located in different geologic formations. Their pore pressure response has been low due to relatively longer construction periods. The deformation behaviour has been similar to the dams constructed earlier. The valley ratio seems to influence the strain condition along the height and longitudinal axis of the embankment darn.

Quest And Probe Related To Erosion In The Wrap-Around Of An Embankment, R. J. R. Cardia

International Conference on Case Histories in Geotechnical Engineering

CESP's divers team found several basalt blocks scattered on the stilling basin of a power plant. Water flowing through bottom outlets was initially supposed to cause erosion in the upstream rip-rap of the wrap-around. Events chronologically reported are: Underwater inspection; removal of materials; monitoring devices behavior; hydraulic tests. Hinder analyses led to recognition of misunderstanding on anomalous mechanism and misconception on the actual sources for the hauled rubbish.

Reconsideration Of Failure Initiating Mechanisms For Teton Dam, G. A. Leonards, L. W. Davidson

International Conference on Case Histories in Geotechnical Engineering

A review of failure mechanisms previously suggested for Teton Dam indicated that they were not fully supported by all the available data. The original mechanisms are reviewed and a failure initiation mechanism is then proposed which does satisfy all the available data, and laboratory tests supporting this mechanism are presented. Additional lessons to be learned from the failure are listed.

Slip Failure Of Embankment On Soft Marine Clay, K. Y. Yong, S. T. Ting

International Conference on Case Histories in Geotechnical Engineering

The results of an investigation carried out at a site before and after the slip failure of an embankment on soft marine clay are presented. An evaluation of the possible causes for the slip failure and the remedial measures taken after the failure are also included. It appears that overstressing of the ground might have led to the movement of the soft soil. The compressible soils were subjected to an increase in stress without a comparable increase in foundation shear strength. This increase in horizontal stress resulted in the horizontal displacement of the soil as evident by the presence of …

Stability Of An Erratic Tailings Deposit, P. C. Kotzias, A. C. Stamatopoulos, B. Karas

International Conference on Case Histories in Geotechnical Engineering

150 million cubic meters of erratic colliery spoils were deposited between 1971 and 1983 close to the Kardia lignite fields, in Greece. The heap finally reached satisfactorily an escalating height of 73 m. Field reconnaissance, collation of local experience and geotechnical investigations were performed during midstage of deposition. They aimed at an optimal configuration of the fill in progress, within the possibilities allowed by extensive earth moving operations. Present paper out- 1ines the approach and the methodology used to arrive at strength parameters and slope design of a highly inhomogeneous massive comprising variegated soils, marls and encaptured lignites.

Stability Of Hill Slopes And Foundation Condition At Radio Astronomy Centre Ootacamand, R. K. Katti, V. S. Chandrasekaran, A. Parthasarathy, K. K. Moza

International Conference on Case Histories in Geotechnical Engineering

Stability aspects of hill slopes and foundation considerations of Radio Astronomy Centre at Ootacamand are described. The analysis of slopes indicated that if joints are not covered, the material in joints may lose strength and the slopes may enter a state of instability. Footings with inclined legs were found to resist the horizontal forces, pull and overturning movements. Lime piles adopted for strengthening soft material at one of the tower locations were found to be effective.