Foundation Wall Research Articles

Deformation-related earth pressure within grid wall-pattern foundation under adjacent surcharge

This study investigated the deformation-dependent earth pressure evolution on the periphery of the grid wall-pattern foundation fully embedded into soft ground. The numerical modelling was performed using the embedded Modified Cam Clay Constitutive model in the FLAC3D software platform and numerical results were validated using centrifuge results. The induced effective vertical and horizontal stresses acquired from the numerical modelling were used to compute the corresponding deformation-dependent earth pressure at different buffer zone distances and surcharge loading. Thereafter, the parameters that influence the determination of the lateral displacement, induced effective vertical stress and deformation-dependent earth pressure coefficient were investigated using machine learning and genetic programming was used to establish the physical equations that could be used to estimate parameters for similar problems. Moreover, for the deformation-dependent earth pressure to be within Rankine's active and passive earth pressure the buffer zone distance/depth ratio should be 10% of the grid wall-pattern foundation embedment into the ground. Furthermore, it was also discovered that the structure fully embedded into the ground under adjacent loading cannot only be designed based on Rankine's active and passive earth pressure investigation on the periphery but the evaluation should be done within the entire location of the grid wall foundation.

New Numerical Technique for the Inbuilt Modified Cam Clay Constitutive Model in FLAC3D

Fast Lagrangian Analysis of Continua (FLAC) is a powerful numerical platform for simulating the deformation and stability of geotechnical structures. Presently, it is documented that the embedded Modified Cam Clay constitutive model in the FLAC platform is deficient in solving geotechnical problems. This paper outlines the new calibration approach by determining the isotropic preconsolidation pressure multiplier based on the relationship between the total stress in the geotechnical problem and the reference pressure. The multiplier was used to establish the nominated maximum isotopic preconsolidation pressure and maximum referential consolidation ratio at the bottom of the soil layer. Subsequently, the maximum isotopic preconsolidation pressure was used to determine the bulk maximum. In addition, the developed approach was used to investigate the lateral displacement of the large grid wall foundation by deep mixing under the adjacent surcharge loading. The feasibility was validated using the centrifuge results. The coefficient of determination between lateral displacement from numerical and centrifuge modelling R2 was 0.95. The proposed numerical technique and calibration approach demonstrated that the embedded Modified Cam Clay model can be used to solve practical geotechnical problems.

Integrating insulated concrete form (ICF) with solar-driven reverse osmosis desalination for building integrated energy storage in cold climates

This research addresses the pressing global challenges of clean energy and water supplies, emphasizing the need for sustainable solutions for the building sector. The study integrates Reverse Osmosis (RO) systems with building energy systems, incorporating Solar Thermal Collectors (STC)/Photovoltaic Thermal (PVT), water-to-water heat pumps, and an Insulated Concrete Form (ICF) based building foundation wall thermal energy storage. It explores the effectiveness of four configurations—STC-ICF, STC-ICF-RO, PVT-ICF, and PVT-ICF-RO—using sensitivity analysis on collector area (25 % and 50 % increase) and weather data from four Canadian cities: Winnipeg, Toronto, Halifax, and Vancouver and two non-Canadian cities: Helsinki, Finland and Bergen, Norway. Key outcomes highlight the benefits of integrated RO scenarios, such as reduced ICF wall temperature, diminished unwanted heat in the cooling season, reduced RO pump consumption, and enhanced solar energy production. The STC-ICF-RO and PVT-ICF-RO systems achieved energy savings of 653 kWh and 131 kWh, respectively, compared to their non-integrated RO counterparts. Both systems also contributed to lowering CO2 production levels. The STC-ICF-RO system's payback period is 2 years, affirming its economic viability. Compared to the base system without ICF and RO integration, the STC-ICF-RO and PVT-ICF-RO configurations reduced energy consumption by 20 % and 32 %, respectively. The sensitivity analysis suggests potential system improvements under specific conditions, primarily when implemented in communities of buildings.

A micro-geoarchaeological look at adaptive and glocal socio-economic aspects: the case of Middle Bronze Age Tel Dor, Israel

Adaptative mechanisms used by coastal urban Middle Bronze Age (MBA) settlements in the southern Levant are regularly studied from the point of view of maritime connectivity. Here we look into the adaptive mechanisms of MBA Tel Dor by investigating the utilization of geogenic (rock, soil, sediment) resources for construction — materials used for wall foundations, mudbrick superstructure and wall plaster — and for pottery making. The composition and fabric of archaeological materials were compared to those of local natural sediments from two boreholes. The results show that stones for wall construction relied on the local kurkar, that red-coloured mudbricks were produced from local Carmel coast sediments, while beige-coloured mudbricks were produced by mixing local red sediments with non-coastal calcareous rock fragments, and that wall plaster was made of non-coastal geogenic marl. From a small pilot sample of pottery, six petrofabrics were identified, including the local Carmel coast, along with five other, distant, production centres. These characteristics suggest that while the site’s inhabitants utilized local resources, they were firmly interconnected with regional, ‘global’, Mediterranean networks, suggesting MBA Dor was a glocalized society, and that diversification of resources served as a promotor of resilience for this coastal society, allowing it to thrive for millennia.

Numerical investigation on ground and structure response of ancient site in complex strata caused by groundwater fluctuation and rainfall

As more and more ancient sites are discovered around the world, protecting them in situ has become a challenge due to issues such as ground settlement and masonry wall leaks caused by groundwater fluctuation or rainfall. In this study, laboratory tests, borehole tests and field high‐density resistivity detections are conducted to obtain information for numerical modelling, including design parameters. A complex three‐dimensional hydrological–mechanical coupling model is then established to investigate ground settlement and wall deformation caused by groundwater fluctuation and rainfall. The seepage simulation results for the initial state are accurately verified by high‐density resistivity imaging. Both measured data and numerical results indicate that changes in a single water head point mainly result in wall settlement. The pattern of wall deformation changes from settlement to lateral deformation with an increase in the drawdown rate of groundwater level. Furthermore, delayed rainfall and high‐intensity rainfall can increase foundation settlement and wall deformation. Settlement deformation determines the upper limit of the global deformation when wall nodes are mainly affected. In contrast, if lateral spreading dominates wall deformation, it determines the lower limit of the global deformation. This study provides reference for in situ protection and foundation reinforcement of ancient sites.

Performance Analysis of Shear Wall Joint Connection in Highrise Building Using Finite Element

Multi-story buildings have a risk of structural failure, especially at joint connections, including raft elements and shear walls, due to the interaction behavior of the shear joints. The problem raised in this research is how to analyze the performance of raft foundation shear wall structural connections in high-rise buildings. The researchers started by simulating the initial model using the element method to find out the detailed capabilities of the raft foundation and shear walls and obtain values that could measure the capabilities of the substructure used. The results of this research explain the results of the evaluation of connection performance, namely, the pile raft phase with fc' 35 MPa and the shear wall phase with fc' 50 MPa. From the analysis in this research, visualization from the ABAQUS program of the force conditions acting on the connection structure was obtained, namely compression damage of 0.0021 at an ultimate compressive stress of 43 MPa and 0.0006 at an ultimate compressive stress of 57.97 MPa. We also perform analytical calculations to determine the tensile and compressive strain values. In the future, it is hoped that it will be possible to make part of the reference the use of connections with similar models and sizes at project work stages with the same characteristics as a contribution to developing building structural safety requirements.

Numerical modelling of pore water pressure response beneath a raft foundation during real river floods

Tall buildings with basement levels are increasingly being built due to need for space in large cities. Frequently, such structures are built involving a raft foundation and diaphragm walls below the water table. In addition, sometimes such buildings are located on floodplains. Therefore, if a river flood event occurs, the building can be exposed to pore water pressure (due to the fluctuation of water table) acting beneath its raft foundation. The generated subpressures will depend on the water table changes with time, and on the way such pressures are transmitted through the ground. Previous works have studied this behavior through laboratory and small-scale tests or numerically; however, many of them have used a constant hydraulic gradient and the water table fluctuations with time have been ignored. In this work, the evolution of pore water pressures with time mobilized beneath a raft foundation of a building built in a floodplain is studied. To do that, full-scale numerical models capable of simulate a river flooding and its corresponding overflow are developed. Such models incorporate data from water table change–time curves recorded during real river floods associated with a set of river regimes. Additionally, the effect of factors such as the soil permeability, the diaphragm wall length, and the soil thicknesses on water pore pressures beneath a raft foundation are also analyzed. Results suggest numerical models developed herein are capable of reproducing pore pressures induced beneath a raft foundation during river flooding. Furthermore, it was found that the above-mentioned factors could impact the percentage of pore water pressure mobilized beneath the raft foundation with respect to the maximum pore water pressure that could be induced during river flooding, and that the principal risk arises in buildings near large catchments where the flow increases over an extended period. Finally, practical implications and recommendations to practitioners are provided.

Experimental Study on the Horizontal Bearing Characteristic of a Strip-Walled Underground Diaphragm Wall

Researching and developing a new type of diaphragm wall foundation can solve the probl em that the traditional diaphragm wall structure may not meet the high standards of safety and stability of underground structures in some specific engineering environments. This paper focuses on the horizontal bearing characteristic of a new form of foundation, a strip-walled underground diaphragm wall, through a series of model tests. In the tests, nine plexiglass models with different section sizes, wall spacings and wall heights, as well as loading strategies (horizontal loads along and against the wall in the model), were conducted. The influence of the above factors on the horizontal bearing performance of the foundation and the soil resistance distribution around the wall was studied. The results show that when the horizontal load applied along the wall is greater than 50 N, the growth rate of total displacement at the top of the wall gradually decreases; when a horizontal load is applied against the wall, with a uniform change in wall height, the optimal wall spacing is 11 cm. When the same displacement occurs, the bearing performance of the model under the former loading strategy is generally 10% higher than that under the later loading strategy. In addition, the depth where the maximum bending moment along the wall occurred gradually moves downward with the increase in horizontal load, and the increase in wall spacing and wall height has a positive effect on the horizontal bearing characteristic. With the application of load, the maximum bending moment of the wall will gradually decrease along the depth. The increase in wall spacing and wall height can improve the overall flexural stiffness and horizontal bearing performance of the foundation. Lastly, the group wall effect coefficient, β, is put forward, and a simplified formula for calculating the horizontal bearing capacity of a strip wall foundation is proposed. In the formula, β is negatively correlated with the buried depth of the wall and positively correlated with the distance between the walls, and its coefficient is greater than 1.

Lateral load response and collapse probability of reinforced concrete shear walls retrofitted for repairability

AbstractThis paper demonstrates the efficacy of a new reinforced concrete shear wall seismic retrofit method through a series of nonlinear static and incremental dynamic analyses. Unlike traditional retrofit methods, the method investigated aims to convert conventional walls into self‐centering walls whose behavior is governed by rocking and flexure. The retrofit involves creating a cold joint at the foundation–wall interface, cutting some reinforcing bars to allow rocking, adding external post‐tensioning to enable self‐centering, and externally confining wall toes to prevent concrete crushing. The retrofit was applied to two building archetypes, each with two different shear wall designs. The four walls were retrofitted by varying retrofit parameters (portion of the vertical reinforcement bars cut, and external post‐tensioning amount). Nonlinear static and nonlinear response history analyses were performed using experimentally validated, computationally efficient models that simulate walls with fiber‐based beam–column elements. Incremental dynamic analysis was used to create collapse fragility functions for pre‐ and post‐retrofit walls. The results show that the retrofit is effective when some vertical reinforcement bars are left uncut across the foundation–wall interface. The retrofit is more effective for walls with vertical reinforcement distributed across cross‐section as compared to walls with reinforcement concentrated near boundary elements and for walls with structurally efficient amounts of reinforcement as compared to walls with higher amounts of reinforcement. This is attributed to the larger amount of reinforcement bars cut in walls with concentrated reinforcement layouts or heavy reinforcement amounts, leading to a larger loss of strength, recovery of which requires larger amounts of post‐tensioning.

Municipal Defensive Walls in Western Poland: The Example of Żagań

ABSTRACT Many relics of municipal fortifications are preserved in multiple cities in the Silesian — Lusatian region. Research works are mainly focused on area such a history, architecture or technical state, without correlation between these areas. The correct approach is to identify walls, or sections of them, as part of parallel, interdisciplinary research that covers the history and chronology of transformations, expansion phases, and their state of preservation which was also the primary and main goal of the research in case of Żagań municipal defensive walls. Thanks to architectural and archaeological analysis, it was possible to determine the chronology of the transformations and layers of the walls. Combining the results of the chronological analyses (C-14, dendrochronology) of wood samples from putlog holes with the results of architectural research allows hypotheses regarding the chronology of constructing objects to be confirmed or excluded. During the study it was found, that it is recommended to correlate the results of archaeological research conducted within the area of excavations next to the foundations of city walls with the results of the structural analyses of soil and water conditions. It is then possible to conduct a comparative analysis of the identified soil and anthropogenic layers. The correlation of architectural research in the field of the chronology of the construction of city walls with the results of the analyses of the cross-sectional deformation of their structure (based on 3D laser scanning) enables answers about the causes of the walls’ inclination to be obtained. The proposed algorithm for interdisciplinary cooperation in research of historical municipal walls is presented.

Modern Restoration Methods For Damaged Historical Buildings As A Result of Military Aggression. Case of Educational Institutions

As a result of the military operations taking place on the territory of Ukraine, thousands of buildings and structures have suffered significant damage and destruction. A substantial share of such buildings belongs to immovable cultural heritage sites, such as historical buildings of local and national significance; frequently, including educational institutions such as kindergartens, schools, lyceums etc. Damaged buildings are subject to restoration by repairing or strengthening their building structures, restoration, or conservation. There is a large number of repair materials and technologies for conducting restoration works, which are regulated by the requirements of DSTU B V.3.1-2:2016. However, while performing repair work on the structures of historical buildings, it is necessary to focus on the DSTU-NB B B.3.2-4 requirements. Among the most common types of damage to historical buildings caused by blast waves, splinters etc., are cracks in the masonry of wall structures and foundations; cracks in the joint of structures; knocking out fragments of masonry with damage to facing; damage to the elements of the floor and covering; systematic soaking of foundations etc. An essential aspect of restoring historical buildings is the maximum preservation of their historical and cultural significance with minimal interventions in the structure of structures and their appearance. The article considers modern methods of restoring the operational suitability of historical building elements, namely repair of cracks by injection and impregnation; strengthening the walls of buildings with the help of external reinforcement with carbon tapes and installation of high-strength rods in stone walls; restoration of stonework using special mixtures; strengthening of reinforced concrete and metal span elements with high-strength carbon fabrics, or lamellas (FRP); installation of waterproofing of walls subjected to systematic locking from the middle of the building.

Numerical-geostatistical-based approach to investigate the earth pressure evolution within the large grid wall foundation under adjacent surcharge loading

This study presents an investigation of the earth pressure evolution within the large grid wall foundation by deep mixing at the expansion site of the Lianyungang port operation. The earth pressure coefficient within the structure fully embedded into the deep soft clay soils cannot only be designed based on the active and passive earth pressure. Therefore, this investigation attempted to use a combination of numerical modelling and post-processing of the numerical results using the geostatistical method to study the critical part of the foundation to endure high earth pressure. The numerical modelling was validated using the centrifuge lateral displacement results. Moreover, the post-processing of the numerical results using geostatistics helped to comprehend the earth pressure evolution within the location of the large grid wall foundation by deep mixing. The Kriging method was found to be the best gridding method based on its high performance and stability on the two datasets that were implemented. The results presented herein depicted that the large grid wall foundation will suffer high induced stresses on the upper part up to the depth of approximately 5 m and as a result it will cause lateral displacement, tilting and shearing off improved soil on the upper section of the foundation. Furthermore, the factor of safety-based numerical and centrifuge shear stress results was 10.14, and 13.79 respectively, while based on the flexural stress from the numerical model the factor of safety was 88.2. Thus, indicating that the large grid wall foundation by deep mixing will be able to withstand the induced stress from the 250 kPa of the surcharge loading.

Uplift behavior of nodular diaphragm wall: Experiment and theory

AbstractThe nodular diaphragm wall (NDW) is a novel foundation that can provide significant uplift load resistance compared to a typical diaphragm wall foundation. With the advantages of low noise, cost‐effectiveness, high work efficiency, and construction abilities close to existing buildings, NDW has excellent engineering application prospects in urbanization construction. However, the scarce knowledge on the uplift resistance, failure mode, and calculation method of the NDW has hindered its application in practice. In this paper, indoor model tests based on particle image velocimetry (PIV) technology are carried out to investigate the uplift behavior of three NDW models with different amounts and locations of nodular parts. The load transfer mechanisms of the three NDW models are discussed in detail, and special attention is given to the failure mode analysis. In addition, a theoretical analysis is implemented based on the load transfer approach. The transfer function and associated critical parameters are discussed in detail. Accordingly, an iterative procedure is proposed to interpret the load transfer information of an uplift NDW in multilayered soils under different loading levels. The findings derived in this paper are helpful to the uplift deformation, capacity calculation, and design of NDW in practical engineering.

Vibration analysis of tanks resting on Winkler and Pasternak foundations

This article presents an analytical technique for determining the free vibration response of a rectangular tank. It is assumed that this structure has a flexible foundation and rigid walls. The effects of beneath soil are considered by using Winkler and Pasternak foundations. To verify the authors’ responses, the finite element solutions are also compared with the analytical results. Additionally, a closed-form approximate relationship is provided in this research work to determine the first natural frequency of the tank resting on a deformable foundation. In order to find the effect of various parameters, such as the stiffness of the elastic foundation and tank dimensions, on the natural frequencies of this system, a sensitivity analysis is also carried out.

Thermal performance of wedge pile slab foundation without frost protection insulation and highly insulated slab on ground floor – first year measurements

In the Nordic countries frost insulation is necessary if the foundation is above the frost-free depth. The thermal performance of the pile foundations is between a shallow ground foundation and a frost wall foundation. The pile ends extend below the frost line to help insulate the ground beneath a building’s foundation. The ends of the piles extend below the frost line to prevent the foundation of the building from frost heaving. However, there may be a risk that the ground below the slab on ground may freeze and frost heaving may occur there. The risk of frost below the slab on ground floor and/or basement increases because increasing thickness of floor insulation remarkable influences frost insulation dimensioning. In this study a 6.5 × 17-meter size uninsulated wedge pile slab foundation with highly insulated (U=0.07 W/(m2·K)) slab on ground floor was constructed for a heated building and equipped with temperature, soil moisture, relative humidity, and heat flux sensors. Seven temperature measurement piles below the building and one for reference 8 meters far from the building reached a depth of up to 3.2 meters, which is deeper than the usual 1.4 m depth to avoid freezing in foundation design. In three places, the temperature below the insulation of slab on the ground is measured at 0.5 meters step up to 3 meters from the outer wall of the building. The first-year measurement results showed that temperature did not drop below the zero degree below the foundation and floor. Even though during winter the daily average absolute minimum temperature was -24 °C the sum of degree hours below the zero degree was -7300 °Ch. The historic 50-year absolute sum of minimum degree hours below the zero degree was -28600 °Ch. In addition to real measurement results this three-dimensional temperature sensor field helps to calibrate and validate dynamic model for temperature simulation of thermal performance of wedge pile slab foundation without frost protection insulation and highly insulated slab on ground floor.

Numerical study on the group wall effect of nodular diaphragm wall foundation in high-rise buildings

Abstract As a new type of foundation, the nodular diaphragm wall (N-D wall) has large transverse stiffness and high bearing capacity, with low noise and low vibration, which is suitable for high-rise buildings in cities with limited land area. The reduction coefficient of each load composition under the same displacement conditions and the ABAQUS finite element numerical analysis software are introduced to analyze the group effect of N-D wall foundations. The results show that the compressive group wall effect coefficient is greater than 1, while the uplift group wall effect coefficient is less than 1. Under the same displacement condition, the group effect of the compressive wall is more obvious than that of the uplift wall, and the group effect of the middle wall is more obvious than that of the sidewall. The wall group effect gradually develops downward with the increase in displacement. The ultimate compressive capacity is mainly controlled by the friction resistance, which is especially obvious in the sidewall. The cap resistance load-sharing ratio decreases first and then increases with the settlement. The cap resistance is not evenly distributed, the stress at the corner is the lowest, and the stress is mainly concentrated in the middle. The influence of wall spacing, length, and width on the uplift bearing capacity is highly significant, while the influence of nodular part angle is slightly significant. The influence of wall width, length, and spacing on compressive bearing capacity is highly significant, while the influence of nodular part angle is weak. The influence of nodular part angle on the uplift bearing capacity of group wall foundation is stronger than that of the compressive bearing capacity.

Nelinearno ponašanje spremnika za ukapljeni prirodni plin s različitim sustavima potresne izolacije

This study determines the effects of different types of base isolator systems on the seismic performance of liquefied natural gas (LNG) storage tanks. Nonlinear time-history analyses of the non-isolated and three different isolated models were performed for the average acceleration of seven ground motions scaled to achieve a specified safe shutdown earthquake. The ANSYS Workbench program was used in the modelling studies of the LNG liquid, inner steel tank, outer shell, ring beam, roof and concrete foundation and side wall insulation. The LS-DYNA program was used for the nonlinear analyses of the LNG liquid, inner steel tank and concrete foundation. The results of the total base shear force, sloshing height, steel tank stresses and lateral deflection were compared. The results indicated that there was no difference between the convective and impulsive modes for the LNG tanks with isolators. It was concluded that the wave motion of the liquid was different from the oscillation of the structure and the earthquake isolation times did not affect the sloshing motion. In the non-isolated system, the stress reached 400 MPa, whereas it was 350 MPa on average in the LNG tanks with isolators.

Numerical modelling of skirted foundations under vertical loads

In the construction of civil structures, the strength of the foundation is of high importance. Thus, engineers face many challenges, such as bearing capacity, settlement and high groundwater level, particularly if the structure is on sandy soil. To deal with these problems, solutions have been proposed, one of which is the use of skirted foundations. In this method, walls skirt the surface foundation and are buried deep in the soil. In this study, numerical analysis, taking into account the parameters of different lengths of skirted foundation walls, different percentages of soil densities and wall thickness, has been used to investigate skirted foundations under static loads. On the basis of the obtained results, a series of charts are presented for estimating bearing capacity improvement. Skirted foundations resting on denser sand provide better results in terms of bearing capacity than foundations resting on medium and loose sand.

Piling Data-Driven Framework for Optimized Pile Structures Based on Minimizing the Expected Total Cost

The use of data in the construction industry is growing rapidly. However, projects that do not have multiple stages, such as pile foundation and cantilever wall construction, are difficult to reinforce based on the data of observation. It cannot be said that the design–build construction process is optimized by piling data and active learning. In this paper, a new data-driven framework is proposed so that it can be used even for construction under single-stage conditions. The proposed method adopts a lower safety factor (SF) in the preliminary design than that in the conventional methods, and checks the performance after the building using piling data. Countermeasures are conducted to satisfy the target reliability, if necessary. Focusing on the expected total cost, the parametric studies reveal that the proposed method can reduce the expected total cost under specific conditions, such as lower countermeasure cost, higher failure cost, and higher relative costs of safety measures. Furthermore, our method exhibits robustness, as even with low initial safety factors, the expected total cost does not become excessively larger compared to the conventional methods. The findings highlight the potential benefits of piling data for optimizing construction projects under single-stage conditions.

OBSERVASI DIAPHRAGM WALL METODE CUT OFF WALL SEBAGAI PENANGANAN REMBESAN WILAYAH WADUK CENGKLIK.

Cengklik Reservoir is one of the tourist attractions in the Boyolali area. Functionally, the Cengklik reservoir is used as a water reservoir or storage area as well as a source of water for the needs of the surrounding community and to supply rice fields. Based on observations, the reservoir has decreased in function, namely seepage is found. One of the methods applied for the handling of seepage is the foundation structure in the form of a diaphragm wall. Observations were started by collecting data (pumping test data and drawings of the diaphragm wall structure). The results obtained for the total diaphragm wall foundation with a depth of 16 m with a depth of excavated soil of 16 m. Specifications for the diaphragm wall plan with a land area of 375m. Diaphragma wall (slurry wall) is a type of plastic concrete retaining wall with a foundation that has very strong rigidity, low vibration during construction, and has a waterproof function. Diaphragama wall provides less seepage effect than other methods such as secant pile. The secant pile only has the same use but differs in area. Cut off wall is a method of excavation work, surrounded by excavated land such as a guide wall. Insulation or retaining water flow on large dam foundations is usually done by the Cut of wall method. This method is suitable for excavation work which is quite deep and dense soil area