Basement Construction Research Articles

Recent development on deep basement construction in soft Bangkok clay next to British Embassy

Recent development on deep basement construction in soft Bangkok clay next to British Embassy

Influence of deep excavation induced ground movements on adjacent piles

In urban areas, excavations for cut-and-cover tunnels and basement construction cause detrimental effects on adjacent existing piles. Hence quantifying the excavation induced lateral deformations and bending moments on piles are important to ensure the stability of structures. In this paper, behaviour of a single pile subjected to excavation induced ground movements is analysed using the finite element method, which has the ability to simulate the construction sequence comprising soil excavation, deformations due to dewatering within the excavation and installation of struts. A fully coupled analysis is carried out based on the effective stress principle. The numerical model was verified using the centrifuge test data found in the literature. A parametric study was carried out to establish the excavation induced pile behaviour varying the depth of the excavation, soil properties, wall support system, pile fixity conditions and pile location with respect to the excavation. Increasing axial load does not have a significant influence on the pile behaviour. However, pile head fixity condition, and stiffness and spacing of the wall support system have a significant influence on the pile behaviour adjacent to the excavation. Finally, based on the parametric study, a set of design charts are developed to predict the pile behaviour by taking into account the depth of excavation, undrained shear strength, width of the pile, spring stiffness, spacing of vertical supports, and unsupported depth of the excavation. The capability of the proposed design charts are demonstrated using a three-dimensional finite element analysis, a case study from the literature and a previously published simplified analysis procedure.

Interaction of the Zymne monastery buildings with the soil base under seismic loads

The work presents numerous research findings on the stressstrain state of a building within the “base–basement–construction” system under a seismic load. The soil array was considered as volumetric nonlinear elastic viscose and plastic environment with a new computed behavioral pattern. The latter accounts for peculiarities of viscose and elastic deformation of marginally stiff soil under a dynamic load, elastic and plastic deformation regarding structural strength and possibilities of strengthening, and energy loss in interaction with the environment. We have revealed the underlying principles of the model. Problems can be solved effectively by the FEM-based variety of the central difference method for heterogeneous systems, which allows to increase the average time integration step and to make effective use of parallel solution methods. As an example, there was created a three-dimensional model of the Assumption (Uspensky) Cathedral of the Zymne Monastery. The modeling was based on the automated system for scientific research “VESNA-DYN” and a modified (explicit) central difference method. According to the findings, seismic loads result in irreversible plastic deformations that significantly impact the stress-strain state (SSS) of constructions. The analysis has exposed the areas of stress concentration that lead to possible damages of constructions. The research has traced emergence and evolution of a tilt resulting from irreversible soil deformations. We have estimated the overall carrying capacity of the church structures.

Observed Performance of the One Museum Park West Excavation

AbstractGround movements observed during foundation installation and basement construction of a residential 53-story RC tower are presented. The One Museum Park West building is located in Chicago, Illinois, and was developed using a combination of bottom-up methods, used for the construction of a central concrete core of the building, and top-down methods to build five levels of basements. The excavation extended 13–15 m below grade and was made through soft to medium-stiff clays. The building was supported by drilled shafts and a perimeter wall formed by secant piles that transitioned to tangent piles below the bottom of the cut. The system was laterally braced with RC floor slabs structurally connected to the secant pile walls and the RC core. Field performance data were collected by means of settlement points and inclinometers located close to the walls on two sides of the excavation. The construction sequence and attendant ground movements during each main activity are summarized. As much as 160 mm o...

Designing and delivering ‘The Cube' mixed-use building in Birmingham, UK

‘The Cube' is an iconic new mixed-used building in the Mailbox development in central Birmingham, UK. Its competition-winning design provided a pragmatic approach to maximising the use of the site but also required a number of complex engineering details to be resolved. This required collaboration between all parties at all stages of the project, making full use of an integrated site office. This paper provides an overview of the project, then describes in greater detail the challenges associated with two of the more complex areas – the large basement construction, containing one of the biggest automated car parking systems in the UK, and the open, irregularly patterned facade structure.

Building response to adjacent deep basement construction

Field observations of the response of a building adjacent to a 23-m-deep basement excavation for a development adjacent to Harrods department store in London, are presented and discussed. This paper focuses on No. 3 Hans Crescent located within the most critical zone, on a re-entrant corner, of the excavation. Top-down construction and underpinning techniques were implemented to minimise ground movements and building damage. Vertical and horizontal displacements were monitored using precise levelling and total station surveys, allowing building responses to be synthesised and related to construction activities. Primary observed and deduced trends are that the effects of underpinning and diaphragm walling were local, whereas piling and excavation had a global impact, and that settlement was primarily caused by diaphragm walling and piling, whereas piling and excavation caused the most horizontal displacement. The zone of influence of horizontal displacements extended farther than that for vertical displacements, which became negligible at a distance of about twice the excavation depth. The No. 3 Hans Crescent property experienced hogging for most construction stages, and sagging developed towards the end of excavation, with in-plane distortions of the building walls and out-of-plane tilting. Observations from monitoring results and post-construction condition surveys indicate that the damage category was negligible, corroborating pre-construction predictions.

Party wall issues on basement projects

The purpose of this paper is to discuss the party wall issues that might arise on basement construction projects, specifically in large, period, high-value London properties. The paper will focus on the rights and obligations of the building owner and the building owner's surveyor, but mention will also be made of the adjoining owner and their surveyor as these roles are inextricably linked.

FINITE ELEMENT ANALYSIS OF DEEP BASEMENT CONSTRUCTION OF BANK OF THAILAND ALONG CHAO PHRAYA RIVER CLOSED TO HISTORICAL PALACES

The Bank of Thailand headquarter (BOT) is a large building located in the innerRattanakosin Island where high-rise building more than 4 storey is not permitted. Thisbuilding consists of 3 story and 5 basements with excavation depth of 15.8 m. The head officewas constructed along Chao Phraya river, the main river of Bangkok. The basement of thebuilding was constructed only 5m and 10m away from two historical palaces, Tewavej andBangkhunphrom. Hence, protection policy has been set for the construction and damageassessment by means of Finite Element Method (FEM) with simulation of basementconstruction method was carried out to predict any potential damage to both palaces. Atlast, the top down construction method was employed for basement construction using1m thick and 20m long of diaphragm wall combined with 50m long of bored pile. Theinstrumentation was installed at the palaces, diaphragm and ground settlement to observefield performance both during and after construction. Furthermore, the field measurement datais compared and discussed with prediction data from FEM analysis and the time dependent oflateral wall movement will be presented. Currently, the construction of Bank of Thailand headoffice is finished without damage to both palaces.

EVALUATION OF PLASTICITY-BASED SOIL CONSTITUTIVE MODELS IN SIMULATION OF BRACED EXCAVATION

Numerical modelling continues to play a unique and intrinsic role in the process of geotechnical design. Of greatest concern are soil c onstitutive models that are employed within finite element software to predict soil behaviour. The objective o f this paper is to provide a numerical study of the Mohr- Coulomb and Hardening Soil constitutive models in simulation of a braced excavation. The Taipei Nation al Enterprise Centre (TNEC) basement construction process was well documented and the commercial finite element code, Plaxis, was selected for this numeric al comparative study. It was found that the Mohr- Coulomb soil model, a first order approximation, pr oduced an underestimation of the diaphragm wall deflection, whilst the Hardening Soil model provide d a good prediction of the observed in-situ diaphra gm wall deflections.

Research on Strength Control and Evaluation of Fly Ash Concrete

This manuscript makes experiments on the relation between each index and fly-ash concrete strength, such as W/B, Sa, S/A and so on. At the same time we applicate artificial neural networks into HPFC The main research is on the relationship between component material and performance of the high-performance fly ash concrete, and also on the fly ash high-performance concrete quality control system and method, which promotes fly ash in foundation and basement construction engineering application. This text introduces the treatment technology of the non-linear artificial neural network, utilizing mixing ratio of existing concrete (import) and data as the performance index (output) to train the network, setting up concrete to non-linear import--Output mode relation, constructing concrete performance model, promoting prediction precision of concrete performance further.

Embodied energy: Soil retaining geosystems

Embodied energy is defined as the total energy in joules that can be attributed to bringing an item to its existing state. This paper attempts to quantify the amount of energy that is put into constructing geotechnical structures. In this study, several common retaining wall options are designed for (i) a hypothetical highway widening project based on a typical condition in London, (ii) basement construction of actual high rise buildings in London and (iii) embankments and cuttings as part of an actual highway road widening project. The embodied energy of each design was computed. Results show that the largest variance on embodied energy is the design solutions and within a given design the materials energy dominates over the installation energy and the transportation energy. The choice of Embodied Energy Intensity (EEI) of materials, particularly steel and concrete, is shown to have a large influence on the magnitude of embodied energy. When comparing among different designs of soil retaining structures, a recycled steel wall system generally has less embodied energy than the equivalent concrete wall system, which is more efficient than the equivalent virgin steel system. Results of the three case studies collectively indicate that minimizing materials usage is the key for reducing embodied energy in soil retention projects.

Heron Tower, London – the strategy for construction

Heron Tower is a new landmark office building in the City of London which is due for completion in February 2011. With 47 storeys above ground and a total height of 232 m, it exceeds Tower 42, which has held the city record for the past 30 years. A steel stability tube structure encloses the office floor plates, carrying vertical and lateral loads to a secant pile wall at ground level, which forms the perimeter of a three-storey basement. This paper describes the construction strategy devised by the designers, with top-down basement construction concurrent with superstructure erection.

Sequential Analysis of Ground Movements at Three Deep Excavation Sites with Mixed Ground Profiles

Field measurements of settlement and lateral deformation obtained from three deep excavation sites constructed in mixed ground profiles are presented and analyzed. Settlement measurements were obtained throughout the construction process, categorized in three stages as: (1) preexcavation (i.e., preliminary site work and support wall installation); (2) main excavation and bracing/anchor installation; and (3) postexcavation (i.e., removal of bracing as basement construction proceeds). Maximum preexcavation stage settlements of 0.03% Hw to 0.06% Hw (where Hw =wall or trench depth) were measured at two sites, with the maximum settlements occurring adjacent to the wall during its installation. Maximum ground surface settlements during the main excavation stage ranged from about 0.15% He to 0.30% He (where He =final excavation depth) and the distribution of ground settlement extended to a distance of 1.5 He to 2.0 He from the wall. Maximum settlements occurred at distances of about 0.3 He to 0.5 He from the wal...

Case studies on bermed excavation in Taipei silty soil

Bermed excavation (deep excavation supported by an excavation wall and a berm) can be an economical method for basement construction in urban areas if ground movement around the excavation is not the primary concern and the excavation site is large and (or) irregular in shape. This paper reviews three bermed excavation projects carried out in the Taipei Basin. One project was successful, one was successful after near failure, and one was a failure. Ironically, extensive ground improvement work had been done for the near-failure and failure cases; but no ground improvement was done for the successful case. It is of interest to find the similarities and differences among these bermed excavation projects. The causes of instability that result in unsuccessful bermed excavation projects and the applications of limit equilibrium analysis to the stability of bermed excavation are also discussed here. These three cases show that the existence of grout columns does not help to effectively increase the stability of the berm if the original safety factor against sliding of a berm slope is less than 1.0 and the improvement ratio of grout columns is low (say <20%).

Apparatus for centrifuge modelling of top down basement construction with heave reducing piles

The construction of deep basements in urban areas is associated with many risks and problems among Which is the possible damage to existing structures and services resulting from settlements near the excavation. A number of methods are routinely employed to attempt to control these movements (e.g. top-down construction, use of stiff diaphragm walls). This paper discusses the methodology and practicalities of a series of centrifuge model tests designed to investigate the effect of deep basement construction. Two sets of experimental apparatus are described in detail and their effectiveness in terms of robustness and generation of repeatable data are assessed. It is shown that using relatively simple techniques and equipment it is possible to model many of the features associated with top-down construction.

Reliability analysis of soil nail walls

In India, soil nail walls are being extensively used for supporting vertical excavations below ground level to accommodate construction of one-or two-storied basements. Generally, the depth of excavations for basement construction ranges from 10 m to 15 m. For such large depth of excavation, variability of in-situ soil properties has significant influence on the stability of the soil nail walls. In the present study, using reliability analysis, an attempt is made to study the influence of variability of in-situ soil properties on the stability of soil nail walls. For better understanding, a case of 10 m high soil nail wall constructed to support a vertical cut is considered for the study and its stability is evaluated for various failure modes. Additionally, the influence of correlation among soil parameters on soil nail wall stability is assessed. In-situ soil friction angle and correlation between in-situ soil cohesion and angle of friction are found to influence soil nail wall stability significantly. In general, reliability analysis provided a better insight into the assessment of stability of soil nail wall.

Chalk anchorages: exhumation load transfer mechanism and design guidelines

An anchorage test programme carried out on the site of a deep basement construction in Norwich, UK, allowed the determination of anchorage capacities and creep characteristic data, and the exhumation of several anchor bodies in chalk. This paper reports on the performance of the chalk-based anchorages, the observation of exhumed grout body shapes and sizes, the extent of grout penetration into dissolution cavities, pressure-grouted fissures, and the formation of grout cake around the grout body periphery. Knowledge of construction techniques utilised for drilling, flushing, pregrouting, redrilling, pressure grouting and the general methods of control implemented to prevent dissolution cavity collapse has been related to the characteristics of the exhumed anchor bodies. Analysis of these grout bodies has allowed the proposal of a failure mechanism, comprising shaft resistance and shear of grouted fissures. Tests were carried out on both conventional and singlebore multiple anchors (SBMAs). Using short, fixed-length capacities with recently developed efficiency factors allowed accurate evaluation of the ultimate capacity of a typical 10 m fixed-length conventional anchorage. This design approach confirms that the SBMA system mobilised double the capacity of a conventional 10 m fixed anchor. Advancements in SMBA technology have enabled designs of 20 m fixed lengths, safely supporting working loads of 3000 kN.

Comparison of retaining walls for basement construction in stiff clays

The selection of retaining walls supporting deep excavations for building basements on various factors such as soil types, permissible movements, construction methods, material and equipment availability etc. For excavations in soft soils, rigid walls such as diaphragm walls and contiguous bored pile walls are commonly used as they are more effective than the more flexible walls such as sheet pile walls, in limiting soil movements to an acceptable level. For excavations in stiff soils, the relative merits for the rigid and flexible walls become less clear. This paper compares the performance and cost-effectiveness of rigid and flexible walls. The relative merits between the rigid and flexible wall systems are discussed.

Ground movements due to pile driving in an excavation in soft soil

An excavation in soft clay for the construction of a deep basement frequently is accompanied by large ground movements that may damage piles preinstalled at the base of the excavation. In a recent project involving the construction of a 10 m wide, 3.7 m deep drain, the construction method adopted entailed excavating the site soils and then driving precast concrete piles. The excavation was supported by steel sheet piles braced by one level of struts. Large settlements and horizontal movements of the ground were observed during pile driving. These movements exceeded those occurring during the excavation phase. Concrete aprons outside a one-story building adjacent to the excavation were badly damaged during excavation and pile driving. However, the building supported on steel piles was undamaged.Key words: deep excavation, sheet piles, pile driving, ground movement, basement construction.

Simulation Modeling and Management of Large Basement Construction Project

Management of a large basement construction project requires careful planning on what to accomplish, identifying all of the activities needed to build it, and obtaining the resources required to carry out the plans. But most importantly, it requires dealing with the changing nature of realities such as inclement weather conditions, equipment or plant breakdown, and delays. This paper attempts to demonstrate how a project manager can rationally and systematically establish a set of project control baselines through the building and use of a dynamic simulation model of a project. The construction of Bugis Junction basement, one of the largest basement construction projects in Singapore, is used to demonstrate the usefulness of the dynamic simulation modeling methodology. The effectiveness of the methodology for improving the different strategies needed at various stages of a construction project to monitor and control project baselines has also been demonstrated.