Engineering Commons^™

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 …

Dewatering, Hydraulic Failure And Subsequent Analysis Of A Sheeted Excavation, G. E. Bauer

International Conference on Case Histories in Geotechnical Engineering

A 16m deep sheeted excavation failed by piping of the base. The sequence of events leading to this failure is described and served as a field case to study the hydraulic nature of the project using flownet, electrical analogy and finite element methods.

Effectiveness Of A Slurry Cutoff Wall At Loeffel Site, G. W. Lee Jr., S. K. Bhatia, G. A. Swenson Iii, S. P. Clemence

International Conference on Case Histories in Geotechnical Engineering

In recent years slurry cutoff walls have been successfully employed to mitigate seepage and isolate liquid waste and leachate in the groundwater environment. However , a success of the slurry cutoff wall depends on the hydrological condition of the site. A post construction and pre-construction groundwater budget analysis can demonstrate the effectiveness of a slurry cutoff wall. In this paper, a detailed groundwater budget analysis of Loeffel site in the Southwestern Rensselaer County of New York is discussed. The analysis shows that the use of a slurry cutoff wall effectively mitigates the release of contaminated groundwater from the site.

Expansive Soil Pavement Design Using Case Studies, G. R. Mckeen, R. L. Lytton

International Conference on Case Histories in Geotechnical Engineering

A study of the field behavior of airport pavements on expansive soils was made for the purpose of developing design procedures for expansive soil areas. Through theoretical developments, computer simulation and empirical calibration a pavement thickness design procedure was developed. The selection of pavement thickness using the method insures a stiff enough pavement to reduce differential movements to acceptable levels based on calculated aircraft response. Differential movements are calculated using a soil model developed from recent concepts of expansive soil behavior. A soil pavement interaction model was derived for calculating the restraint provided by pavement stiffness.

Failure Of A Salt Aragonite Storage Pad, Yong S. Chae

International Conference on Case Histories in Geotechnical Engineering

A case study of the performance and failure of an aragonite and salt storage pad covering an area of approximately 250 ft. (76 m) square built on marginal subsurface conditions is reported. A detailed analysis of the failure illustrates the importance of thorough exploration of subsurface conditions and field instrumentation to monitor the performance of such storage pads during and after the loading period.

Foundation Movement Monitoring Of Heavy Structures – A Case History, M. R. Lewis, A. Sanver

International Conference on Case Histories in Geotechnical Engineering

Accurate monitoring of settlement beneath the main structures of a nuclear power plant not only demonstrates the stability of the structures, but also confirms predicted settlements, thereby verifying the geotechnical parameters used in the design. At the Grand Gulf Nuclear Station near Port Gibson, Mississippi, rebound and settlement monitoring has been continuous since the start of site excavation in 1974. As a result, actual settlements have been shown to be close to the predicted levels. This paper discusses the planning, installation and monitoring of the settlement instrumentation and reviews the factors that were important to the choice of instrumentation.

Foundations On Friction Creep Piles In Soft Clays, Sven Hansbo

International Conference on Case Histories in Geotechnical Engineering

In this lecture, a new principle for design of building foundations on friction piles in soft, cohesive soils is presented. Four case records on buildings designed according to the new principle are analysed in respect of total and differential settlement. In two cases, a comparison has been made with buildings on conventional friction piles. The savings in foundation cost of the buildings designed with creep piles is evaluated in relation to buildings designed with conventional friction piles. The lecture is a synthesis of research and development carried out together with Leif Jendeby, M.Sc., Chalmers University of Technology and Rolf Källström, …

Ground Response, Baltimore Lexington Market Tunnels, J. G. Engels, S. J. Calabrese

International Conference on Case Histories in Geotechnical Engineering

Soil response data and the results of soil deformation analyses are presented for twin tube rapid transit tunnels constructed in soil. The data collection and analyses were performed during the construction of the Lexington Market Line Tunnels in Baltimore, MD between 1977 and 1980. Sources and volumes of ground loss around the tunnels and the resulting ground surface settlement patterns are discussed. Analyses are presented indicating that substantial volume expansion of the soil over the tunnel occurred during construction. Comparisons are made to similar analyses of data reported in the literature for other tunnels driven in similar geologic conditions.

A New Version Of Rectification For The Leaning Structures And Foundations, Yi-Ji Wang, Jian-Xin Yuan

International Conference on Case Histories in Geotechnical Engineering

A new version of the rectification technique tor the leaning structure and foundation developed by Wuhan Foundation Engineering Center was used to restore the tilted columns to their original position. The main idea of this new method is to apply adjusting loads on the foundation through anchors or short piles. According to the tilting conditions the anchors or piles can be installed at one side or at both sides of the tilting foundations. The loads can be applied in successive increments until the final desired positions were reached. By using this technique a tilted warehouse was completely restored to its …

Behaviour Of Bridge Abutment On Fractured Chalk, A. Marsland, A. P. Butcher

International Conference on Case Histories in Geotechnical Engineering

Loading tests on 865 mm diameter plates showed that the fractured chalk was much more compressible than at other sites on the same deposit but it was still considered that slab foundations would be adequate for the bridges at most locations. Detailed measurements have been made on one of the bridge abutment foundations both during and following construction. Measurements were made of vertical pressures applied to the ground, lateral earth pressures acting on the abutment wall, settlements of the foundation slab, tilt of the wall, and vertical displacements in the ground below the foundations. These observations confirmed the adequacy of …

Caisson Design By Instrumented Load Test, D. J. Lane

International Conference on Case Histories in Geotechnical Engineering

Three instrumented axial load tests were performed on 42 inch diameter caissons (drilled piers). These caissons were installed in marine sediments of dense sand overlain by soft sand-clay mixtures. Correlations were made with the Standard Penetration Test to develop design relationships. Production caissons were then designed based on these relationships. Test caissons were approximately 54 feet long and installed by the slurry displacement method. Test loads were carried to 1,000 tons. Mustran cells were used to determine loads in the caissons at different depths. Resulting data is presented graphically as load versus settlement, load versus depth (load distribution), and side …

Chimney Foundation On Drilled Piers, K. Y. C. Chung, L. D. Cundy

International Conference on Case Histories in Geotechnical Engineering

This paper describes the design and compares predicted performance to actual responses of a drilled pier foundation supporting a 305m high chimney. The purpose was to evaluate laboratory and empirical side friction and end bearing criteria used in the pier design. Based on results of a subsurface exploration program, and consideration of vibration effects on nearby structures, a foundation system was designed consisting of 38 drilled piers capped with a concrete mat. The piers had an average diameter of 1.37m in soil and 1.22m in rock. The average length of pier was 15.63m including a rock socket 2.44m deep. Each …

Combined Earth And Rock Bearing Foundation - Hospital Humana Mexico City D.F., Michael R. Stomer, Pablo Girault, L. E. Wilson

International Conference on Case Histories in Geotechnical Engineering

This text describes the design and performance of a shallow spread footing foundation system for a large medical care facility in Mexico City. The project is unusual because the spread footings bear on a combination of basaltic lava and coarse sand fill containing angular lava fragments, the latter of which was densified using the dynamic deep compaction process. In the following narrative, the exploratory program is described, the geotechnical design and construction process is explained, and the inspection procedure for footings bearing on rock and soil is discussed. Further, the results of precise settlement monitoring for the structure are presented.

Damaging Settlements Of A Building Due To Gypsum Dissolution, Minh Phong Luong

International Conference on Case Histories in Geotechnical Engineering

Geotechnical facts are presented relating to the damaging settlements of a building due to gypsum dissolution in the subsoil. Settlement records on the damaged building over a period of 15 months after first disturbances are given in correlation with the ground water pumping volumes from a well located in the neighbourhood in order to attempt a comprehensive interpretation of this case history.

Deformation Of Slopes Of Two Excavations In Soft Clays, C. W. Sheng

International Conference on Case Histories in Geotechnical Engineering

Observed results concerning the movements of excavated slopes during and after excavation for two drydocks with different construction sequence have been described. FEM analysis has been conducted and discussed. The effect of heavy rains on the stability of slope improved by wellpoints has been presented.

Discussions And Replies, E. J. Armstrong, G. W. Plant, D. H. Shields, John P. Sully, H. Taylor, R. K. Katti, Shri K. K. Moza, Shri D. R. Katti

International Conference on Case Histories in Geotechnical Engineering

No abstract provided.

Down Drag On An Instrumental Bored Pile In Soft Clay, R. K. Bhandari, M. R. Soneja, Devendra Sharma

International Conference on Case Histories in Geotechnical Engineering

The paper reports result of a comprehensive full scale field study expressly undertaken to monitor negative drag on a large diameter, bored cast-in-place reinforced concrete pile installed to rock in a deep deposit of soft marine clay of pleistaceae to recent origin. The pile was instrumented with load cells and the ground around the pile with piezometers and settlement gauges. The negative drag was generated by loading the ground around the pile in stages. The ground settlements were accelerated by providing vertical sand drains. The observational data were utilized in figuring out the influence of surcharge on the depth of …

Dynamic Precompression Treatment - A Case History, F. J. Leon

International Conference on Case Histories in Geotechnical Engineering

An unusual case history of a condominium apartment building, originally designed for eleven storeys, to which four additional floors were added after the footings had already been constructed and was successfully completed to fifteen storeys in height . The use of rather high soil-bearing values, from 7 ksf ( 350 kPa) in the original design to over 12 ksf ( 600 kPa) . The project site , underlain by erratic soil profiles containing layers of soft fine-grained soils to about 20 ft (6 m) below the surface, had been effectively improved with an intense application of the Dynamic Precompression Treatment …

Effect Of Foundation Deformations On The Damage Of A Masonry Villa (Case History), S. A. Abo-El Magd, H. M. Hosny, M. Mashhour

International Conference on Case Histories in Geotechnical Engineering

Cracks in the masonry walls of a one storey villa due to foundation deformations are investigated in this paper. In spite of the fact that the soil formation in the site was found to be almost uniform, hogging deformation profile took place in the strip foundation due to unequal loading. Analysis of the walls together with their supporting soil, as one integrated system, showed that very small foundation deformation can produce tensile stresses in the wall higher than its tensile strength. Repair of the cracks was proposed and carried out successfully.

Field Consolidation Of A Moderately Organic Hetrogeneous Deposit, P. D. Deo, A. S. Mehta

International Conference on Case Histories in Geotechnical Engineering

Very little technical information is available in literature about the compressibility characteristics of peat and organic soils. The problem of estimating consolidation settlements is even more complex for moderately organic hetrogeneous soils, such as mixtures of organic and inorganic soils.

Two known factors affecting compressibility characteristics of organic soils are: natural moisture content and consolidation pressure. From several sites, natural moisture content and compressibility data was collected for organic soils. The data is presented graphically for low and moderate consolidation pressures.

On the basis of the above mentioned data, coefficient of compression index for a moderately organic deposit was estimated. …

Field Observation Of Pore Pressure In Soft Clay, R. L. Wei

International Conference on Case Histories in Geotechnical Engineering

Pore pressure measurements made during the preloading of a large oil tank on a deep deposit of soft clay are reported and analyzed. The piezometer data show that the excess pore pressure at a point in the subsoil increases linearly with the increasing surface load until a certain critical load is reached. Then the induced shear stress at that point reaches the shearing strength of the soil, and local yield occurs. Henceforth there is a pronounced increase in the observed rate of pore pressure built-up.

Foundation Heave At Asco Ii Nuclear Power Plant, R. B. Fallgren, C. R. Mcclure

International Conference on Case Histories in Geotechnical Engineering

Excavation of 75m of claystone at Asco Unit II resulted in foundation heave in excess of anticipated elastic rebound. The heave was found to be caused by expansive clay minerals in the rock swelling in the presence of water. Upper-bound estimates of future heave were made based on past trends, and structures analyzed to demonstrate their capacity to resist heave-caused deformations. The primary factor in controlling heave is the amount of water available to the bedrock.

Foundation Problems And Solutions At The Bridge River, Powerhouse No. 1, H. Taylor, A. P. Joseph

International Conference on Case Histories in Geotechnical Engineering

The Bridge River Powerhouse No. 1 was constructed between 1946 and 1950 on the north shore of Seton Lake near Lillooet, British Columbia, Canada. The Powerhouse contains four Pelton wheel (impulse) turbines generating a total of 200 MW of electrical power. When the powerhouse was completed and the first units placed in operation severe and extensive ground cracking occurred behind and beyond the powerhouse. The ground movement shifted the powerhouse slightly toward the lake, and cracked the concrete penstock tunnels. As a result of this the foundation under the powerhouse was thoroughly investigated and instrumentation installed to record and assess …

Geologic Considerations In Civil Constructions - Malaysian Case Studies, Boon K. Tan

International Conference on Case Histories in Geotechnical Engineering

The need for adequate geologic input into civil engineering projects is common knowledge to all. However, quite surprisingly, in many construction projects in Malaysia geologic input is either totally lacking or highly inadequate. An indicator of the extent of neglect of geologic input into civil constructions in Malaysia is the fact that many soil investigation reports for these projects in this country do not contain a section or even a brief write-up on the site geology. This paper presents several case studies of civil engineering projects where geologic factors have been overlooked, thus resulting in the delay in the completion …

Ground Heave Due To Pile Driving, J. P. Dugan Jr., D. L. Freed

International Conference on Case Histories in Geotechnical Engineering

The factors which influence ground heave due to pile driving outside the construction site are discussed. Elevation survey data are presented for nine case studies in the Boston area where the subsoil conditions consist of an insensitive clay deposit in the range of 60 to 110 feet thick. Curves of heave vs. normalized distance exhibit a trend of increasing heave with increased volumetric displacement ratio. Patterns of ground heave typically occur as radially shaped contours decreasing in magnitude away from pile driving. Building and ground movements observed several years after completion of pile driving indicate that the heave is temporary, …

Grouting To Control Deep Foundation Settlement, B. Mcclelland, E. J. Ulrich

International Conference on Case Histories in Geotechnical Engineering

An 18-story reinforced concrete building under construction in South Florida reached 16th floor level when significant differential settlement presented an unanticipated foundation problem. The foundation consisted of a structural mat supported by 14-in. concrete piles 24 to 75 ft long. Surprisingly, the longest piles were within the area of greatest settlement. Investigation revealed a previously undisclosed semi-cavernous zone from 120 to 175 ft below ground surface, and level surveys using deep benchmarks confirmed that zone to be the source of movement. Injection grouting first accelerated and then controlled the settlement, allowing the building to be completed on schedule. Temperature probes …