Search Documents

By Chen Xizhe

The caisson is adapted to the foundation of concentrated heavy building. As there are the flowing sand, boulder or cobble and other serious obstruction, the open caisson can't sink, the caisson can solve these problems easily. Especially for the stability of the neighour building, the merit of the caisson is outstanding. Therefore, there are the pier, the foundation of heavy instrument and the large water pumping station etc. using the caisson in China. This paper introduce several caissons and successful experience by author's investigation. It contains the feature and application of the caisson : the examples of caissons such as a huge pier of a bridge acrossing a big river, a large instrument foundation and a large water pump station beside a river; the problem of the design of the caisson and notice items during the caisson construction etc.

Jan 1, 1991

By Gregory A. Stephan

A case history of design, prediction, probe pile driving, and construction of a pile foundation for Building 3 of Waterside at Bay Beach Condominiums located in Fort Myers Beach, southwest Florida, is presented. Site geometry constraints, the presence of a 12.0 ft (3.6 m) deep lake occupying the southern one-third portion of the proposed building footprint, and marginal subsoils provided specific challenges for design and construction of the foundation. The subsoil conditions were explored by performing Standard Penetration Test (SPT) borings and a Piezocone Penetration Test (PCPT) Sounding to depths of 100 ft (30.5 m) within the building footprint. Additionally, borings were performed to envelope the building. Deep foundation alternatives included driven concrete, monotube, and steel pipe pile as well as drilled shaft. Following an evaluation of high structural loads, site-specific constraints, foundation test data from buildings 1 and 2, and preference expressed by the project owner, a pre-cast prestressed concrete (PPC) pile-supported foundation system was selected as an economical and effective foundation approach. Use of an augered cast-in-place (ACIP) pile foundation system was precluded by the project structural engineer. This paper deals with the design aspects and methodologies utilized in choosing and economizing the foundation system. The building foundation was designed for an allowable pile capacity of 40 tons (353 kN) in compression, 1.5 tons (12 kN) in lateral capacity for a deflection of 0.25-in (0.64 cm) and 15 tons (133 kN) in uplift capacity. For the single story extended garage structure, a pile capacity of 27 tons (238 kN) was indicated in compression. As part of the design process, an extensive probe pile driving program was carried out in order to evaluate the pile driving equipment, determine and verify pile capacities, and optimize the production pile lengths. A total of 33, 14-in (356 mm) square, PPC concrete piles were driven within the entire building limits, and dynamically load tested utilizing Pile Driving Analyzer (PDA) as part of the probe pile driving program. Utilization of PDA during probe pile driving helped in predicting pile set-up (i.e., increase in pile resistance with time) as well as reducing the pile lengths by as much as 20 percent. It resulted in variable pile lengths during the production phase. This information was effectively utilized as part of the overall quality control program to install a total of 559 PPC piles (including 33 probe piles) within the Building 3 footprint, including the reclaimed lake area, to depths ranging from 45 to 58 ft (14 to 18 m) below existing ground elevation as part of the foundation support system. Prior to installation of probe or production piles, a termination criterion was established using 1-dimensional wave equation analyses in addition to the design pile embedment requirement. The predicted pile capacities compared reasonably well with the capacities from the CAPWAP analyses for probe piles. This engineered, monitored and tested foundation solution provided a cost effective and satisfactory basis for completion and approval of the foundation work for the building resulted in cost savings over other foundation alternatives for the owner. The building has since been occupied and a recent reconnaissance has indicated that the building foundations are performing satisfactorily.

Jan 1, 2003

By David G. Winter

The first test pile for the carrier pier and south wharf at NAVSTA Puget Sound was driven on December 27, 1989, and the final pile was tested on February 26, 1990. Implementation and modification of the test pile program were done by the owners (WESTDIV and ROICC-Everett), the engineers (ABAM and Hart Crowser), and the contractor and his subcontractor (General Manson Joint Venture and GRL). The site is located as shown on Figure 1. SUMMARY OF THE SOIL CONDITIONS A soil profile along the pier is shown as Figure 2. The soil units can be generalized as follows: ? Upper Silts - Fill, sandy silt, and clayey silt extending from the mudline to an elevation of about -80 feet; ? Intermediate Sand - A medium dense to very dense silty sand unit which is about 30 feet thick near the shore, but thins and disappears offshore; ? Lower Silts - Sandy silts and clayey silts in a medium stiff to stiff condition; ? Deep Sand - A very dense overconsolidated sandy soil encountered at an elevation of about -145 feet.

Jan 1, 1990

By Craig T. Jones, Zachary Q. Maassen

"Jet grouting is a method of ground improvement that relies on the erosive capacity of high-speed jets to cut and mix the ground in place with a cementitious grout. A continuous return flow of cuttings, called jet grout backflow or spoils, is expelled to the surface during the grouting process. Data from projects completed in Toronto and Ottawa is presented where BOS Solutions’ services provided significant savings compared to the traditional spoils treatment utilizing vacuum trucks for spoils disposal. These traditional treatment methods are cumbersome and expensive by nature. BOS Solutions provided an alternative solution that is environmentally friendly and capable of handling full flow to process these jet grout spoils utilizing a tank system paired with centrifuges and flocculation additives to remove the ground soils and grout product from the spoils slurry. BOS’ process produced a clean water for reuse in the project while reducing the overall waste volume by producing a dry, stackable solid that could be hauled to a landfill. Benefits observed by using the BOS process were disposal waste volumes decreased over 30% and at least a 19% reduction on disposal costs.SCOPE OF WORKJet grouting is a method of ground improvement that relies on the erosive capacity of high-speed jets to cut and mix the ground in place with a cementitious grout. A continuous return flow of cuttings, called jet grout backflow or spoils, is expelled to the surface during the grouting process. The backflow, or spoils, is a mixture of grout, water and soils. Traditionally, the spoil would be collected in in-ground pits and allowed to solidify for a few days prior to hauling to a final disposal site. For the projects completed in Toronto and Ottawa, the jet grouting work was performed at street level, in high traffic congested areas, presenting the challenge of insufficient space for the contractors to process the jet grout spoils in the traditional way. At first, attempts were made of using vacuum trucks to collect and haul the wet spoils to an off-site location where the spoils would be allowed to solidify. However, this method proved cumbersome and expensive due to the high volumes of spoils generated daily and the high number of vacuum trucks required to support the jet grouting operations, respectively."

Jan 1, 2017

By Jason N. Scott

CFA piling is a ?blind? construction process that relies heavily on the rig instrumentation to produce sound piles. If the data measured and recorded during construction can be made available to engineers and managers within hours after construction then there are many economic and quality control benefits that can be realised. A state of the art CFA instrumentation and data management process has been developed in the UK. The key components of the instrumentation, GSM data service and the central database are described. Many benefits to the business have been realised and, where possible, these are quantified.

Jan 1, 2006

By Sangseom Jeong, Kyoungyul Kim, Jaeyeon Cho

"Abstract The lateral earth pressure of vertical circular shaft is investigated by using experimental tests and a theoretical analysis. The emphasis was quantifying on the magnitude and distribution of a lateral earth pressure measured by three-dimensional arching effect. A framework for determining the earth pressure distribution on the basis of both centrifuge model and full-scale field test results is introduced. Through these studies, it is found that the lateral earth pressure decreases within active displacement (dh/H: 0.2×10-2, dh: horizontal displacement, H: Height of vertical shaft) of wall at deep excavation and the arching effect is more significant for deep excavation than for shallow excavation. It is also found that the lateral earth pressure acting on a vertical circular shaft considering arching effect is 70% smaller than that calculated by Rankine theory, and thus represents a significant improvement in the prediction of realistic earth pressure for vertical circular shaft subjected to arching pressure.INTRODUCTIONIn South Korea, an increasing need for underground excavation and the application of the vertical circular wall (i.e. vertical shaft) is becoming an important issue in engineering practice. Here the vertical circular wall is generally embedded in soft or hard rocks through weathered soil varying thicknesses ranging up to 15 m. Since 1980, a number of huge excavation projects such as underground space for constructing power stations, subways, high-speed railways, and many lifeline constructions have been performed in urban areas (Jeong and Seo, 2004). Although there have been considerable advancements in construction techniques involving vertical circular wall, it is still very important for tunnel engineers to control the lateral earth pressure. Additionally, Proper estimation of earth pressures is a key factor in design of vertical circular wall. Because of three dimensional arching effects, i.e. convex arching and/or inverted arching, the earth pressure acting on a circular type of wall is less than other types. Thus, the vertical circular wall is generally used."

Jan 1, 2014

By John E. Lens

Minutes after the Friday afternoon October 16, 2009 announcement that the 80 year old Lake Champlain Bridge was closed to traffic out of concern for public safety, emergency detour planning started at VTrans and NYSDoT. The closure severed a cross-lake link between Addison, VT and Crown Point, NY, which created a 76 mile detour and significant hardship for commuters, farmers working on both sides of Lake Champlain, and businesses relying on both traffic and employees commuting between Vermont and New York. Rehabilitating the bridge was determined to be economically and technically unfeasible and the design of a replacement bridge was accelerated for a spring 2010 construction start. In the meantime, a temporary ferry alternative was to be rushed into service beside the original bridge by February 2, 2010. This paper presents the case history of the fast-tracked ferry dock design and construction on the Vermont side. Twin 300-foot-long pile supported approach spans, a loading slip system and ice deflectors were designed, fabricated and constructed in 90 days in the fall/winter of 2009-2010. This chronicles the project from initial concepts through the extraordinary cooperation between state and federal agencies, and near round-the-clock winter construction on Lake Champlain. This project and its companion project on the New York shore succeeded by virtue of exceptional cooperation between seasoned regulatory, design, and construction participants and warrant this case-history presentation of the Vermont project to share within the industry as an example of overcoming extraordinary challenges.

Jan 1, 2011

By Inn-Joon Park

Major problems associated predicting soil-structure interaction behavior are based on the fact that soil is neither homogeneous nor elastic and soil properties are spatially variable. There also exist significant coupling problems between the behavior of the structure and geologic media. When designing foundation or other geotechnical structures, the load transfer between the soil and structure takes place at the contact surface. This surface is called the interface. The behaviors of interface play an important role in the load-deformation response of soil-structure interaction systems. The purpose of this study is to develop improved model for simulation of saturated sand-steel pile interface behavior based on a general concept, called the disturbed state concept (DSC), which can characterize the behavior of saturated soils under dynamic loads. In this study, the Disturbed State Concept (DSC) constitutive model is calibrated and modified for steel pile-saturated sand interface and interaction by using the continuous hardening model for relative intact (Rl) state and the critical state model for the fully adjusted (FA) part in the saturated sand material. The general formulation for implementation has been developed. Then, the DSC model with modification for interface and saturated sand is implemented in finite element program based on the generalized Biot's theory. The interface tests under one-way monotonic and two-way cyclic loading and cyclic triaxial tests are executed for defining the parameters for interface and surrounding soils. Based on these parameters, steel pile-saturated sand interface and interaction are numerically simulated using the finite element program modified in this study. The DSC predictions show improved agreement with the observed results from laboratory test.

Jan 1, 2002

By Robert B. Bittner

The Sutong Bridge across the lower Yangtze River in China will have, when completed, the longest span (1,088 m) and the highest towers (306 m) of any cable stayed span in the world. The foundations for this record setting span will also be record setting. They are located in water depths exceeding 30 m with maximum flows exceeding 3 m/sec. The soil at the site of the main pylons consists of layers of silty sands and silty clays extending to bed rock at 270 m below river elevation. This paper describes the innovative methods used by the team of foundation designers and constructors to support this record setting bridge at this very challenging site. This paper covers three specific topics related to the foundations of the Sutong Bridge: ? Design and construction of the 131 drilled shafts (2.8/2.5 m diameter and 114/117 m long) under each of the two main pylons, including the post-grouting of all drilled shaft tips. ? Design and construction of the scour protection for the two main pylons. ? Construction methods used to construct the waterline pile caps (113.8 m by 48.1 m by 13.3 m deep) under each pylon.

Jan 1, 2007

By Maurizio Siepi

The realisation of most of the civil engineering works is subordinate to the execution of consolidation works, in order to improve the soil physical-mechanics characteristics. The works classifiable with the term "Soil Improvement" can be realised using several technologies, among which the Deep Mixing Method is distinguished for his remarkable flexibility and productivity characteristics. The Deep Mixing Method is a process whereby a rotary drilling machine mechanically drills a constant diameter hole while cement slurry is injected into the soil at high pressure. The process combines state of the art construction techniques merging mechanical and hydraulic mixing energies at the tool bit. The result is a soil-cement column of engineered strength, consistency and dimension. Whereby the soil cement column formation process is controlled by a computerised device, the result is a speedy installation, thorough mixing, and a high degree of control, repeatability and documentation.

Jan 1, 2002

By Martin J. Kenwright

Within the famous Harrods department store, a new lift shaft has been constructed, servicing a depth of 22m below ground level as well as the existing 6 storeys of the store. The shaft will connect with a new goods tunnel which is to be excavated beneath the shop, as well as new floor space above ground level which has resulted from the infilling of a previously existing lightwell within the store. The construction of the deep shaft while maintaining uninterrupted use of the store by the Client led to a number of innovative solutions being undertaken. Empirical assessments were made of settlements anticipated from the construction process, which took place within a congested environment of existing foundations. Various elements were designed and installed to mitigate the effects of the inevitable ground movement on the surrounding overlying structure, which supported sensitive high quality finishes and mechanical and electrical installations. The reinforced concrete lining of the shaft was contained within a cofferdam of minipiles. The minipile placement accuracy (1 in 150) was vital as it could not interfere with the subsequent tunnelling works. As the scheme progressed this became even more critical since the minipiles were needed as support for parts of the permanent works. This paper describes:- the high quality placement and control of the minipiled cofferdam, the methods employed in assessing ground movements and the techniques used to mitigate against the effects of these movements.

Jan 1, 2000

By Takefumi Takuma, Masashi Nagano, Christopher DellAringa

Multiple agencies in Southern California are retrofitting and upgrading their levees to catch up with ever-advancing urbanization affecting the requirements for existing channels and levees in this seismically active zone. Pressed-in sheet piles have been specified on some of these projects to minimize noise and vibration problems associated with sheet pile installation. This paper will study three Southern California levee and sewer pipeline retrofit projects that utilized pressed-in sheet piles in hard soil conditions with N-values higher than 50. BACKGROUND Southern California is home to numerous drainage channels fortified with earthen levees. In spite of the region’s semi-arid climate with varying annual precipitation from year to year, winter storms can bring in heavy and continuous rainfall to the area which overwhelms the levees’ capacities at times. Some levees are running through densely populated areas with homes and other sensitive structures such as underground utilities and bridge piers. Conventional sheet pile driving utilizes either percussive or vibratory pile driving methods, both of which generate high levels of noise and vibration, causing nuisance and potential damage to nearby structures. On the other hand, the press-in piling method utilizes a hydraulic force to push piles into the ground, thus practically eliminating the noise and vibration issue. Although there are types of press-in piling systems mounted on tall leaders on large crawler-base machines, they are less frequently used due to its much larger size and more limited drivability than the type discussed hereunder. The other type of press-in machine sits on top of already installed piles and is anchored with its own weight and additional counter weight when starting off as shown in Figure 1. Once the first few piles are pressed in, the equipment grips on top of the installed piles and moves forward on its own as the pile installation progresses. See Figure 2. This method does not use a vibratory or percussive force to install piles.

Jan 1, 2018

By Niels Krebs Ovesen

Close economic cooperation was established among the countries in western Europe during the seventies. As a consequence, among others, a need for harmonized technical specifications for civil engineering works arose. Technical specifications for design and execution of building and civil engineering structures exist in most of the European countries. In some countries such technical specifications are part of the building regulations and in other they are independent codes of practice and standards. The works on the Eurocodes was initiated by the Commission of the European Communities about 1976. The Eurocodes are intended as common unified design codes for different load bearing structures constructed from different materials. They are also intended to cover design of geotechnical structures. They are established with a view to promote the free movement of goods and services within the member states of the European Community - the so called Internal Market - and within the member countries of the European Free Trade Association, EFTA by removing obstacles arising from different rules for calculation and design.

Jan 1, 1994

By Pasi Korkeakoski

There are about 400 multi-storey buildings founded on wooden piles in the city centre of Turku in Finland. Soil conditions are variable from hard rock to very soft clay. Due to the soil conditions and ground water lowering there are basically four different types of underpinning projects. Under dimensioned cohesion piles in a deep clay layer, decaying cohesion piles, a combination of these two reasons and decaying end bearing piles in a thin clay layer area. Many different execution methods have been used such as impact driving, jacking and drilling and combinations of these.

Jan 1, 2000

By Lawrence F. Johnsen

In 1989, the Connecticut Department of Transportation authorized the evaluation and design for a reconstructed Route 1 bridge over the Quinnipiac River in the City of New Haven, Connecticut. The project extends from the intersection of Route 1 with East Street, easterly for approximately 3/4 mile to the intersection of Route 1 with Wheeler Street and Stiles Street. The reconstructed roadway will be relatively on-line and widened to provide for four lanes of vehicular traffic and a single-track railway line. The existing bascule bridge and approach spans, which were constructed in 1924, will be replaced by a 270-foot span lift bridge and new approach spans. The lift bridge will have a main lift span weighing approximately 3000 tons, second largest after the Burlington Northern Bridge over the Williamette River in Portland, Oregon. The new bridge will widen the navigation channel to 24 0 feet and provide vertical clearances of 13 feet when closed and 62 feet when open. The project is located in an industrial area. Adjacent properties include retail gasoline sales, auto repair, railroad transport and bulk storage of petroleum. Existing structures include the Yale Boathouse and several retaining walls serving as containment dikes for petroleum storage tanks. The Yale Boathouse, located on the east bank of the river, was constructed in 1909-1910 and is eligible for listing in the National Register of Historic Places.

Jan 1, 1993

By Dan Brown

This paper presents a case study of a cyclic lateral pile load testing program performed on two 18-in square prestressed concrete piles (PSC) in Savannah, Georgia. The load test program was developed to simulate the lateral behavior of a single pile under seismic loading conditions for the design and construction of a large LNG storage tank. The lateral load tests included cyclic loading to measure possible degradation in soil response followed by static loading to large displacements (around 6 inches at the loading point). The lateral load was applied through a reciprocating jack positioned to push and pull the piles against each other. The test piles were instrumented with multiple displacement transducers, downhole inclinometer, and strain gauges. This paper provides an interpretation of the test results regarding the pile performance and soil response to monotonic and cyclic lateral loading. A backfitted computational model of the soil resistance was developed to match the test results using the LPILE computer program. The load-deflection and deflection/moment versus depth comparisons suggest that this model appears to capture the behavior relatively well within the general range of suitability for design purposes. New design curves were developed based on the soil parameters derived from the lateral load test results.

Jan 1, 2003

By Franz-Werner Gerressen

"The use of soil improvement to utilize areas, which are not suitable for foundation purpose, has a long tradition. Due to the increasing demand of foundation works in areas of unsuitable soils, the improvement of the existing soils becomes even more important in the future.Various applications and systems for various demands exist around the world. Either it is a “simple” improvement for settlement reduction or a more important aim as liquefaction mitigation. However, each system has its advantages, limits and needs.Furthermore to the soil improvement, using various tools, soil mixing can also be used for applications like cut off and/or retaining wall.The paper will describe some basics of various techniques and different applications of the systems all over the world where the systems provided solutions for different purposes, e.g. simple foundation or liquefaction mitigation.It will describe also the main equipment which will be needed to execute these works under the various conditionsINTRODUCTIONSoil mixing is a methodology where the soil is improved by mixing it with cement, lime or other binders in situ by using a mixing tool. This methodology can be used either as wet mixing or as dry mixing. In the more frequently used wet mixing process, usually a mixture of binder and water, maybe with additives, is injected and mixed with the soil. Depending on the type of soil and binder, by the end of the mixing process, a mortar like mixture is created which hardens during the hydration process. In the dry mixing process, the binder is directly mixed with the soil and reacts directly with the existing soil and water.Mixing tools show several versions, so that they are mixing around either a vertical or horizontal axis, mixing in a trench and maybe are jet assisted. Figure 1 shows a classification done by Bruce 2010. Depending on the technique, improvement depth of up to 80 m can be achieved."

Jan 1, 2017

By Sachihiko Tokunaga, Hirofumi Taguchi, Kenji Maruyama, Hidenori Takahashi, Yoshiyuki Morikawa

"Abstract The present study proposed a new liquefaction countermeasure to improve sandy ground and conducted a trial execution. The new method is a floating-type and lattice-shaped cement treatment method, where cement-treated soil is not fixed to a non-liquefiable stratum. A fixed structure such as treated soil should be formed at the side of the floating-type treated soil to reduce its lateral displacement. In the study, one-dimensional dynamic response analyses were first conducted to confirm the mechanism of the new method. Then, a series of centrifuge model tests were performed to demonstrate the effect under a stress condition at the prototype scale. The analyses and model tests confirmed the effect of the liquefaction countermeasure. Finally, trial executions were carried out to confirm high-quality vertical execution.INTRODUCTIONLiquefaction induced by an earthquake generates sand boiling and ground settlement. Other problems have also been reported, including a decrease in bearing capacity and an increase in the horizontal earth pressure against retaining walls. To prevent these problems caused by liquefaction of the ground, various countermeasures have been proposed, such as cement deep mixing and high-pressure jet mixing methods. These methods have the big advantage of being applicable to ground that contains soil with a fine-grain fraction. Furthermore, the unnecessary displacement caused by the construction can be reduced. In Japan, a lattice-shaped cement-treatment method has frequently been used at many construction sites to prevent liquefaction, where cement-treated piles are intersected to form a lattice, as shown in Fig. 1. The lattice-shaped walls can reduce the shear stress generated by an earthquake, restricting the liquefaction at that location. However, the construction cost of the cement treatment is relatively high compared to other methods such as the sand compaction pile (SCP) method, and needs to be reduced. In particular, the cost of the high-pressure jet mixing method, which can be applied to the liquefiable ground under existing structures, is significantly high. Therefore, decreasing the total volume of the cement treatment is necessary to reduce the construction cost."

Jan 1, 2014

By Li Keqiang

Among the pile foundations of the 156 tall buildings over 18 storeys in Shenzhen, 86. 5% of them are constructed by slurry drilled piles, bored piles and excavated piles (hand-dug caissons). Based on the experiences of the engineering practices, the paper points out that the main quality problems of pile foundations in Shenzhen are: insufficient bearing capacity of single pile; poor concrete quality of pile; damage of the precast pile; pile tip not reaching the required bearing stratum and the thickness of bored/drilled sediment exceeding the specified. etc. The quality inspection methods that have been used include: check of construction records and excavating; static loading test; core sampling test; non-destructive test, etc. Treatments of quality problems used in Shenzhen are also introduced in this paper.

Jan 1, 1991

By Klaus Pöllath

This paper describes mitigating measures and the design of compensation grouting which will be executed from deep shafts of the Amsterdam North/South Metro line project. Due to the specific conditions for TBM-tunnelling in Amsterdam (historical buildings on pile foundations near the tunnel and soft soils with high groundwater levels) tunnel construction necessitates mitigating measures, such as compensation grouting or soil freezing. Züblin developed a special shaft construction method for critical distances to buildings. For the compensation grouting Züblin developed a new software tool, called SOFIA, which controls and visualizes and thus optimizes the entire injection process. This tool significantly increases the efficiency of the injection works while reducing the geotechnical risks.

Jan 1, 2006