Wall Project Research Articles

The Effects of Anchor Configurations and Field Characteristics on Anchored Diaphragm Walls

Diaphragm walls are the ideal solution for productive utilisation of underground space to meet modern-day demands of infrastructural developments. Selection of appropriate wall and support configurations has substantial impact on economy, time and performance of diaphragm wall projects. Unsatisfactory implementation of such retaining systems during or after construction may cause heavy causalities such as loss of life and damage to adjacent infrastructures. Practical significance of excavation induced deformations is large due to its potential damage to adjacent structures. Hence, reliable estimates of excavation related responses are vital for construction and implementation of embedded diaphragm walls. This paper presents results of parametric analysis performed on anchored diaphragm walls evaluating the effects of anchor configurations and field characteristics. Numerical studies are carried out to comprehend the influence of factors like ground conditions, excavation geometry and anchor characteristics. Walls embedded in cohesive and non-cohesive soils with varying ground water locations are considered for analysis. Anchor features including length, inclination and axial prestress are varied in combination with the above parameters. The effects of these factors and their combined influence on the deformation, flexural strength and axial capacity of diaphragm walls are determined and evaluated. Numerical analyses are carried out using finite element simulations with Plaxis 2d. Comparative charts are drawn to demonstrate the variations of wall responses with different combinations of influencing factors. Optimal configurations of diaphragm wall and anchor system for different ground conditions can be perceived from the result charts.

Labor Productivity Improvement Obtained by Masonry Walls Project Design Implementation

Abstract This paper aims to quantify the labor productivity improvement reached by the implementation of a masonry wall project design to guide field construction. A masonry wall project design is an instrument of rationalization, developed to specify the layout and steps of a masonry walls execution. The methodology is of quantitative nature and involves a practical case. The work of an enterprise in Goiânia (Brazil) was tracked by the collection of productivity data, firstly of a crew that didn’t have access to a masonry wall project design, and then of a crew that had access to the project. The evaluation of the productivity improvement was processed by means of statistical analysis, such as location and dispersion measures, average and variance, T-test, and F-value. Hypothesis tests were also performed to prove that the changes in productivity were caused by the implementation of the masonry project. The results showed that the project deployment optimized the production process in the field. There was a 26% increase in the team average productivity with access to the project design according to the hypothesis tests. The main contribution of this work is to present the beneficial impact of a masonry wall project design tailored for field construction, which allows a formal and rational approach to a heavily artisanal technique.

Assessing health impacts of an environmental pan-African development project: A migration perspective.

The general objective of this article is to analyze to what extent the implementation of the Great Green Wall project is likely to disrupt migratory movements towards the rural environment and, consequently, the socio-economic structures and health status of local populations. This study was carried out in 2015 on a population sample of 500 individuals living in the municipality of Tessekere, constructed using the quota method. Socioeconomic and demographic characteristics, migratory status and self-rated health of individuals were collected during face-to-face interviews. Statistical analyses used were Chi-square tests, student and binary logistic regressions. Results show that internal migrants in the municipality of Tessekere represent 13.40% of the study population. Migrants more often work as civil servants, artisans, craft workers or traders than the region's native population, who are generally livestock breeders or jobless. While place of birth does not play a significant role, it appears that the length of residence of migrants in rural areas influences health status: migrants residing in the municipality of Tessekere for less than 10 years are less likely to report poor health, regardless of their sex, age, occupation, material well-being and perceived stress. In conclusion, an environmental requirement (combating desertification), addressed by an international political project - the Great Green Wall - and then applied at the national level, has transformed the demographic, economic and health structure of a local population. In conclusion, our study showed that (1) an examination of migration can offer a means of interpreting the impact of development projects and the local changes they entail, and (2) migration is a unique prism through which one can study how exposure to a new physical and social environment influences the health of populations.

Making Management (More) Relevant: Breaking Down Disciplinary Walls and Pursuing Neglected Independent Variables

The Walls Project encourages educators to broaden management teaching beyond individual and organizational variables and outcomes to systemic variables and outcomes. Its focus is on discovering independent variables that have social and environmental impacts and are currently neglected. Founded by six individuals who met at a RMLE UnConference in 2017, the Project decided to share pedagogical materials, examine them for commonalities, and present their findings at the MOBTC conference in 2019. This article summarizes these materials with an eye to revealing several variables of consequence, such as socioeconomic status and belief in economic growth, which are studied and taught infrequently in business schools. We suggest that researchers examine business curricula for similar neglected variables, study their impact across systems levels, and then develop them pedagogically to enhance management education that has a social and environmental impact.

Impacts of land cover changes on desertification in northern Nigeria and implications on the Lake Chad Basin

Desertification is an issue of environmental concern in Nigeria, particularly the northern part of the country. This study examines land cover changes related to the process of desertification in the states along the northern boundary of Nigeria (Sokoto, Zamfara, Katsina, Jigawa, Yobe, and Borno) and the implications on the Lake Chad Basin. A time series of Landsat imagery at a spatial resolution of 30 m was used over the period from 1984 to 2016. The imageries were subjected to maximum likelihood classification for the purpose of extracting the land cover and analysing the change. Also, the areal extent of vegetation cover within the 32-year period was calculated annually. Using Pearson's correlation analysis, the relationship between the vegetation cover and rainfall was assessed as well as temperature and population density. Results show that 45,945.08 km2 of vegetation cover was lost within the study area including the Lake Chad area between 1984 and 2016. The annual rate of change varied across the different feature classes; the built-up area had the highest rate of increase of 13.68% and 2.65%, from 1984 to 2000 and 2000–2016 respectively. Bare-land increased at the rate of 0.96% and 0.28% from 1984 to 2000 and 2000–2016 respectively while vegetation had the highest rate of decrease of 2.18% and 2.02% from 1984 to 2000 and 2000–2016 respectively. A pattern of vegetation loss was observed as a large expanse of vegetation cover was lost across the north-west and the north-east regions including the Lake Chad area. It was also shown that the magnitude of vegetation cover correlated negatively with temperature and population density but with no significant correlation with the rainfall. The study recommends that the Federal Government should ensure the full implementation of the Great Green Wall project which is aimed at mitigating the rapid sprawl of natural land degradation processes and desertification in the northern boundary states.

The Unity Wall project: a student-led community organizing effort to advance public discourse on social justice

ABSTRACT Socially-unjust public discourse targeting disadvantaged and oppressed populations has increased in intensity and acceptability in the United States. In response, social work students designed and implemented a community organizing effort, The Unity Wall, to provide community members with an opportunity to anonymously share personal responses to current discourse on racial tension and other current events. This paper describes the implementation and evaluation of the Unity Wall, as well as the evaluation findings and implications for using this community-organizing approach in other community settings.

Thinking beyond success and failure: Dutch water expertise and friction in postcolonial Jakarta

In 2014, a consortium of Dutch firms revealed the master plan for Jakarta’s Great Garuda Sea Wall project, combining urban development and flood risk management. Though a ground-breaking ceremony was held, little progress has since been made, and the yet-to-be materialized project faces an uncertain future. Taking this project as its case study, this article examines the efforts of Dutch consultants to realize the proposed Great Garuda Sea Wall project in Jakarta, and the frictions encountered during this process. This article contributes to a growing scholarship in policy mobilities that interrogates instances of policy failure. I begin from the premise that there are valuable insights to be gleaned by examining projects and policies that occupy the space in between failure and success. By using the lens of friction, this article aims to think beyond these categories and their limitations. I demonstrate how friction can be simultaneously productive and disruptive to policymaking and mobilizing, therefore complicating binary representations of success and failure. Abandoning these limiting categories holds the possibility of enriching policy mobilities scholarship by opening up space for analyses of the messy and indeterminate processes that are central to policymaking, and which categories of success and failure are unable to capture. This is especially important for understanding policymaking in the context of the “global South” where projects often remain unrealized and such categories are less analytically useful.

Research on Hoisting Method of Reinforcement Cage for Underground Continuous Wall

The hoisting method of reinforcement cage in a diaphragm wall project is studied. Through certain graphic display, the process of hoisting the reinforced cage was described. In this paper, we propose a specific method of hoisting a 880mm thick of reinforcement cage, and the entire specific process and technology of lifting it is also offered. During the hoisting procedure and the lifting transformation process, reinforcement cage hoisting is an important part of construction, and this article has certain reference value to the construction process.

Research on Quality Evaluation Method of TRD Cement-soil Continuous Wall Based on Analytic Hierarchy Process

In order to accurately evaluate the wall quality of cement-soil mixing wall by TRD method and reduce the risk of foundation pit excavation, this paper proposes a comprehensive evaluation method of wall quality. Based on strength analysis, impermeability analysis, borehole TV analysis and electromagnetic borehole radar analysis, the main influencing factors of TRD cement soil wall quality are analyzed and determined. Using the analytic hierarchy process, the hierarchical structure model of the wall quality evaluation index system is established and the evaluation factors are quantified. The fuzzy comprehensive evaluation method is used to evaluate the index factors. By analyzing the evaluation results, the evaluation grade standards of excellent, good, medium and poor reflecting the wall quality are established. The evaluation system and grade standard are used to evaluate the wall quality of waterproof curtain in a station foundation pit of Qingdao metro. The actual excavation of the foundation pit is basically consistent with the evaluation results. It has preliminarily realized a change from qualitative and empirical to scientific and half quantitative. The research results can be promoted and applied to the similar TRD cement soil mixing wall project in the future.

The origins of novelty from within the confines of homology: the developmental evolution of the digging tibia of dung beetles.

Understanding the origin of novel complex traits is among the most fundamental goals in evolutionary biology. The most widely used definition of novelty in evolution assumes the absence of homology, yet where homology ends and novelty begins is increasingly difficult to parse as evo devo continuously revises our understanding of what constitutes homology. Here, we executed a case study to explore the earliest stages of innovation by examining the tibial teeth of tunnelling dung beetles. Tibial teeth are a morphologically modest innovation, composed of relatively simple body wall projections and contained fully within the fore tibia, a leg segment whose own homology status is unambiguous. We first demonstrate that tibial teeth aid in multiple digging behaviours. We then show that the developmental evolution of tibial teeth was dominated by the redeployment of locally pre-existing gene networks. At the same time, we find that even at this very early stage of innovation, at least two genes that ancestrally function in embryonic patterning and thus entirely outside the spatial and temporal context of leg formation, have already become recruited to help shape the formation of tibial teeth. Our results suggest a testable model for how developmental evolution scaffolds innovation.

Purification of the Air in the Historic Cities of Towns

Air pollution observed from the beginning of the industrial age has had a negative impact on the health, quality and life expectancy of the inhabitants of urban agglomerations. The problem of particulate and gaseous pollutants in PM 10 fine particulate matter and PM 2.5 suspended in air is a particular threat. The emission of harmful substances is spatially and temporally differentiated in the urban area and depends on the degree of urbanization and the level of vehicular traffic as well as the season of the year. City centres filled with compact buildings of historic character are a special issue in the planned and implemented urban regeneration strategy. The multidimensional issues of the protection of the historic structure of the city centre are more and more important in the aspects of revitalization processes in line with the sustainable development of cities. The surface of the facades of the tenement houses currently undergoing renovation works can be used as planes used with the help of the latest technological developments for air cleaning processes. The first part of the article presents technical and technological possibilities applicable to the development of facades of architectural objects. In addition to vertical garden technologies, which are increasingly successfully used in architectural realizations, the latest developments in technology and material engineering, including the importance of titanium dioxide (TiO2) - TiO2 nanoparticles, as a component of building and finishing materials, such as cement and facade paints. Titanium dioxide from the 20s of the 20th century was used as an effective component of paints with excellent properties of opacity and bleaching pigments. Building materials containing TiO2 nanoparticles have revolutionized the building materials market at the beginning of the 21st century thanks to their special selfcleaning, bactericidal, anti-static and air-cleaning properties. These materials have also been used in conservation work. The second part presents examples of implementation of conservation measures using the latest material technologies and examples of green wall projects and the effects of these works. To sum up, the article focuses on the issue of facades in architectural objects of inner-city buildings and adaptation possibilities of these areas for the purpose of air purification and improving the quality of life of urban residents. The revitalization activities implemented in the spirit of sustainable development are currently correlated with the challenges for contemporary measures to protect cultural heritage.

Impact of mycorrhiza-based inoculation strategies on Ziziphus mauritiana Lam. and its native mycorrhizal communities on the route of the Great Green Wall (Senegal)

A wide program of fruit tree planting, notably jujube trees, has been implemented in the framework of the pan-African Great Green Wall (GGW) project to improve food security in arid and semiarid regions. However, the success of such initiatives is highly limited by a low tree growth and high tree mortality rates due to transplant shocks from tree nursery to field. The positive impact of mycorrhiza-based ecological engineering strategies on jujube trees were previously demonstrated in nursery conditions, but field monitoring is necessary to evaluate their sustainability in terms of plant growth and survival. In the current study, local (Tasset) and exotic (Gola) jujube cultivars were tested for their response to mycorrhizal inoculation with the non-native arbuscular mycorrhizal (AM) fungus Rhizophagus irregularis IR 27 and fertilization with rock phosphate. The environmental impacts of both treatments were assessed by characterizing the native AM fungal community in a 13-month-old jujube orchard. Field results demonstrated higher rates of survival and a relative stability of nursery-driven plant benefits of inoculated jujube trees, as well as a potential higher persistence of AM fungal inoculum for the exotic cultivar. The native AM fungal community associated with the local cultivar was the most diverse, but Glomeraceae was predominant in both cultivars. The mycorrhiza-based ecological engineering strategies proposed in this work affected both AM fungal communities, notably Glomeraceae and Gigasporaceae members, but in a higher extent for the local jujube cultivar. Results highlight the strong benefits of mycorrhizal inoculation at the very early stages of tree seedling growth in nursery and their stability in the first year of plantation. Nevertheless, a deeper assessment of mycorrhizal inoculum persistence and spread, and a wider characterization of soil and root microbiome need to be implemented in further field monitoring to better evaluate the environmental impacts.

Three-dimensional numerical modelling of geocell reinforced soils and its practical application

This paper proposes a new numerical approach to model geocell reinforced soils, where the geocell is described as membrane elements and the complex interaction between geocell and soil is realized by coupling their degrees of freedom. The effectiveness and robustness of this approach are demonstrated using two examples, i.e., a geocell-reinforced foundation and a large scale retaining wall project. The first example validates the approach against established solutions through a comprehensive parametrical study to understand the influence of geocell on the improvement of bearing capacity of foundations. The study results show that reducing the geocell pocket size has a strong effect on improving the bearing capacity. In addition, when the aspect ratio maintains the same value, the bearing capacity improvement with increasing geocell height is insignificant. Comparing with the field monitoring and measurement in the project, the second example investigates the application of the approach to practical engineering projects. This paper provides a practically feasible and efficient modelling approach, where no explicit interface or contact is required. This allows geocell reinforced soils in large scale project can be effectively modelled where the mechanism for complex geocell-soil interaction can be explicitly observed.

U.S.-Mexico border: the wall of strife

So much has been said about the US southern border in the first two years of Trump presidency that it may seem he was the author of the wall project. Meanwhile it has been 100 years since the US-Mexico border fencing construction began. The first fence was put up during the First World War, chapter two in the history of the wall (1993-2000) led to 200 km of fencing. 2006 marked the beginning of an ongoing third and most ambitious stage of the thousand-kilometer barrier construction. Sealing off the remaining 2 000 km of the border became D. Trump’s main pitch during the election campaign, but in two years of his presidency no additional segments were actually built. After Congress refused to finance construction to the extent requested by the president, D. Trump declared a state of emergency, which implies redistributing Ministry of Defense budget funds, bypassing Congress in order to re-equip 376 km of the fence and build about 160 km of the wall. But the history of the American wall and the Israeli security barrier (which D. Trump likes to exemplify) shows that the construction is effective only as long as it is combined with the high-tech tracking methods that in the US can be introduced as of now, without building a physical barrier.

Installation Technology of Super Long Steel Hanger for Curtain Wall of Xi’an Silk Road International Convention and Exhibition Center

There are 268 pieces of super long steel hangers on the façade of the curtain wall project of Xi’an Silk Road International Convention and Exhibition Center. A single piece of steel hanger is 26m~44m long and 7t~34t heavy. The difference between this project and the conventional construction method of curtain wall lies in that during the installation of steel hangers, the complex deformation of the main steel structure can make it difficult to accurately install steel hangers. The construction steps are simulated with SAP2000. The simulation defines 84 construction steps. After an accurate calculation of the deformation of the main steel structure that each piece of steel hanger must adapt to, the super long steel hangers are assembled on site. The overhanging end of the metal roof is about 5m~20m from the mounting axis of steel hangers, so the conventional process of installation from up to down cannot be applied. A 180T crawler crane is utilized for overall lifting and installation on the side. This is a new construction method of curtain wall that can control the installation accuracy within 5mm, ensure the flatness of the structural façade, improve the construction and installation efficiency, and guarantee the construction safety. It can provide a technical reference for similar large-scale curtain wall projects in the future.

Evaluation of tensile load model accuracy for PET strap MSE walls

There are conflicting opinions regarding whether or not mechanically stabilized earth (MSE) walls constructed with polyester (PET) straps should be classified as relatively inextensible type, and thus fall into the same category as steel reinforced soil walls, or whether they should be viewed as relatively extensible and grouped with MSE walls that are designed with geosynthetic sheet reinforcement such as geogrids and geotextiles. The differences in predicted loads using models associated with each category can be significant. The writers collected 71 measurements from eight different instrumented PET strap wall projects. The data showed that these PET strap walls behaved more like extensible geosynthetic walls constructed with geogrids and geotextiles (or at least at the stiffer end of these walls) rather than MSE walls with relatively inextensible (steel) reinforcement. The accuracy of the Coherent Gravity Method, the Simplified Method and the Simplified Stiffness Method was assessed statistically using analysis of bias values, where bias is the ratio of measured to predicted load. The Coherent Gravity Method and the Simplified Method resulted in conservative (safe) estimates of reinforcement loads under operational conditions on average. However, the Simplified Stiffness Method was the most accurate and did not result in an excessive level of conservativeness.

Material migration and fuel retention studies during the JET carbon divertor campaigns

The first divertor was installed in the JET machine between 1992 and 1994 and was operated with carbon tiles and then beryllium tiles in 1994–5. Post-mortem studies after these first experiments demonstrated that most of the impurities deposited in the divertor originate in the main chamber, and that asymmetric deposition patterns generally favouring the inner divertor region result from drift in the scrape-off layer. A new monolithic divertor structure was installed in 1996 which produced heavy deposition at shadowed areas in the inner divertor corner, which is where the majority of the tritium was trapped by co-deposition during the deuterium-tritium experiment in 1997. Different divertor geometries have been tested since such as the Gas-Box and High-Delta divertors; a principle objective has been to predict plasma behaviour, transport and tritium retention in ITER. Transport modelling experiments were carried out at the end of four campaigns by puffing 13C-labelled methane, and a range of diagnostics such as quartz-microbalance and rotating collectors have been installed to add time resolution to the post-mortem analyses. The study of material migration after D-D and D-T campaigns clearly revealed important consequences of fuel retention in the presence of carbon walls. They gave a strong impulse to make a fundamental change of wall materials. In 2010 the carbon divertor and wall tiles were removed and replaced with tiles with Be or W surfaces for the ITER-Like Wall Project.

“An Imagined Border of Safety, Humanitarian Relief, and Creativity”: J.M. Design Studio’s Other Border Wall Project

In April 2017, J.M. Design Studio—three Pittsburgh-based artists and designers—responded to the Customs and Border Protection's public request for proposals for a wall along the US-Mexico border. J.M. Design Studio then announced their own call for more border "wall" proposals from other artists. The following commentary details these prototype concepts and tracks the executive policies and rhetoric that established a foundation for the border wall. This commentary also shows how J.M. Design Studio’s prototype submission and the subsequent artistic platform they initiated both model how creative connection and the co-option of established public channels are themselves acts of political resistance in an era of disrupted democratic participation and ossified partisanship.

Is Jakarta’s New Flood Risk Reduction Strategy Transformational?

On a conceptual and normative level, the debate around transformation in the context of disaster risk reduction and climate change adaptation has been rising sharply over the recent years. Yet, whether and how transformation occurs in the messy realities of policy and action, and what separates it from other forms of risk reduction, is far from clear. Jakarta appears to be the perfect example to study these questions. It is amongst the cities with the highest flood risk in the world. Its flood hazard is driven by land subsidence, soil sealing, changes in river discharge, and—increasingly—sea level rise. As all of these trends are set to continue, Jakarta’s flood hazard is expected to intensify in the future. Designing and implementing large-scale risk reduction and adaption measures therefore has been a priority of risk practitioners and policy-makers at city and national level. Against this background, the paper draws on a document analysis and original empirical household survey data to review and evaluate current adaptation measures and to analyze in how far they describe a path that is transformational from previous risk reduction approaches. The results show that the focus is clearly on engineering solutions, foremost in the Giant Sea Wall project. The project is likely to transform the city’s flood hydrology. However, it cements rather than transforms the current risk management paradigm which gravitates around the goal of controlling flood symptoms, rather than addressing their largely anthropogenic root causes. The results also show that the planned measures are heavily contested due to concerns about ecological impacts, social costs, distributional justice, public participation, and long-term effectiveness. On the outlook, the results therefore suggest that the more the flood hazard intensifies in the future, the deeper a societal debate will be needed about the desired pathway in flood risk reduction and overall development planning—particularly with regards to the accepted levels of transformation, such as partial retreat from the most flood-affected areas.

Radical Women: Latin American Art, 1960–1985, Pacific Standard Time Festival: Live Art LA/LA

Radical Women: Latin American Art, 1960–1985, Pacific Standard Time Festival: Live Art LA/LA