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This document is a closure to a case study on ground subsidence caused by the drying effect of Australian native eucalypts. The study highlights the potential for clay soil shrinkage and subsequent damage to structures such as residential buildings, road pavements, and pipelines. Recommendations for addressing the drying effects of trees on nearby buildings vary by country, with the Australian standard AS 2870 providing guidelines for designing footings near trees. The closure also addresses potential queries from practitioners, including the age of the trees, the construction date of the netball court, and the impact of cutting tree roots during barrier construction. The writers express gratitude to Dr. Vishnu Diyaljee for their insights and thank the discusser for their valuable questions and additional insights. [Extracted from the article]

This article discusses a case study on the effects of ground subsidence caused by the drying effect of a group of Australian native Eucalyptus trees near a netball court. The study demonstrates the impact of evapotranspiration on the cracking of the court and highlights the importance of monitoring sap flow from trees to understand water movement. The article also compares the recommendations for tree placement near infrastructure in Canada and Australia, emphasizing the need for geotechnical engineers to consider the influence of trees on foundation distress. The study suggests the use of root barriers and collaboration with agriculturists to mitigate tree-induced suction and prevent settlement issues. The article concludes by calling for a reevaluation of the Canadian Foundation Engineering Manual to address the influence of trees on foundation behavior. [Extracted from the article]

The serviceability limit of the foundation system plays an important role in the safe long-term performance of a building. Under governing load cases in service life, the building foundation system should satisfy the serviceability limit state, i.e., total and differential settlement criteria. This study investigated the distress of a building through foundation performance assessment incorporating the soil–foundation–structure interaction (SFSI) effects. A spatially variable soil model [zonewise, obtained from field observation and electrical resistivity tomography (ERT) study] was used to obtain the settlement of the foundation system. Engineering properties of the subsurface were estimated from the collected soil samples and field tests. ERT result shows the variability of the subsurface layer. A three-dimensional finite-element model of soil, foundations, and structures was developed to estimate the settlement demand of the foundation and structures. The numerical model includes the geometric variability of all the foundations of the building and subsurface variability. Settlement and bearing capacity demand of the foundations were estimated and compared with the standard provisions. Results obtained show that the building foundation system satisfies the serviceability limit of the foundation system under total settlement criteria. However, the differential settlement of the system exceeds the required limit despite considering the SFSI effects, and is one of the major causes of distress to the building. The main contributions of this study also include establishing the spatial variability of the soil layer through ERT and correlating it with the crack zone in the building. [ABSTRACT FROM AUTHOR]

Soft soil foundations are often encountered in engineering construction. To make the foundation meet the engineering strength and deformation requirements, the soft soil foundation must be treated. Based on bucket foundation and silt solidification technology, the new grid composite foundation is proposed. The strength improvement mechanism of the new type foundation was analyzed according to the Mohr-Coulomb strength theory, and numerical simulations are used to carry out research on the bearing characteristics of the grid composite foundation. By carrying out load simulations for the grid foundation with different foundation widths, the failure modes corresponding to different B/L were analyzed. With overall consideration of the side length of a solidifying grid, the foundation width, and the undrained shear strength of the soil mass, the calculation method for the bearing capacity of the grid composite foundation has been proposed. Moreover, a wall strength check is carried out according to the maximum pull stress of the solidified wall. In the field test, the results of the finite element simulation and the field test are in good agreement, further verifying the feasibility of the grid structure foundation. Thus, a theoretical reference for engineering design is provided. [ABSTRACT FROM AUTHOR]

This paper presents a case study of applying a new device termed deformation adjustor in piled raft foundations to support a highrise building. The deformation adjustors are mounted on a pile head to optimize load distribution of a piled raft foundation so that a relatively uniform foundation deformation can be achieved in complicated load, construction, and soil conditions. In this case study, the project site is located in a coastal city in China, featuring complicated subsurface soil conditions with abundant large boulders. The project was put on hold for a decade because in the complicated soil conditions the piles could not be installed to the required depths. The project resumed with introduction of deformation adjustors which helped to shift the applied loads from piles to subsoil below the raft and thus considerably reduced the pile lengths. This case study describes the preliminary design of pile-raft foundations with deformation adjustors, followed by a comprehensive monitoring program for settlements, earth pressures, and pile top reaction forces during and after building construction. Based on the long-term monitoring, subsoil below the raft was able to bear 83% of total applied loads, whereas the piles carried 17% of the loads. Based on this case study, deformation adjustors were proved to be an effective and economical solution for piled raft foundations to support high-rise buildings in complicated subsurface conditions. [ABSTRACT FROM AUTHOR]

The lifecycle analysis and assessment of concrete structures requires an efficient evaluation and prediction of time-variable mechanical and chemical degradation processes. Inspection systems and novel monitoring methods are of valuable support in these important tasks, but due to their practical feasibility and the costs that they entail, they also present limitations. Therefore, information gathered with inspection methods for structural performance assessment needs to be used in the most effective manner possible, e.g., with respect to serviceability limits, bearing capacity, robustness, and redundancy of a given structure, among others. The aim of this paper is to present a framework for the prediction of time-dependent performance indicators of concrete structures prone to fatigue, with emphasis on a wind turbine foundation, including reliability. A theoretical background and selected structural performance indicators as well as associated lifecycle prediction methods--incorporating inspection and monitoring information--are presented. [ABSTRACT FROM AUTHOR]

This paper describes a systematic approach of inspection, diagnosis, and repair for masonry walls and their claddings, aiming at facilitating the inspection process and deciding on the repair of these elements. It also helps to combat their degradation. Based on a visual analysis, the inspector is able to identify anomalies and use the proposed system tools to establish correlations with its source, delineate an accurate diagnosis, and determine the best repair technique. The tools that allow a faster and simpler inspection and decision are presented here. The nature of the anomalies, their related causes and appropriate repair techniques are classified, listed, and then related through correlation matrices to create a database. This equips the inspectors with the information they need about the pathology in masonry walls, as well as its classification through suitable terminology, so that a statistical analysis can be performed to find the chief causes of the anomalies. The system was developed under a strategy of proactive maintenance, and it represents an innovation that is as useful to rehabilitation in southern Europe as it is in other regions where masonry walls are a widely used technique. [ABSTRACT FROM AUTHOR]