Housing and Development Board

Geotextile tube is a popular solution for dewatering applications. During the dewatering process, infill material is pumped into the geotextile tubes through the inlet port at high pressures, and thus significant amount of tension forces can be developed at the inlet port sleeve and connecting parts of the tube. Geotextile tearing could occur at these locations during high pressure pumping. Therefore, it is important to determine its resistance to tearing and the factors that affect its tearing strength. So far, only limited studies have been done on this aspect. Hence, a new tensile test setup was developed to simulate the application of tensile forces on the inlet port sleeve and surrounding geotextile material during slurry pumping. The setup consists of a housing to clamp a portion of the geotextile tube body, and a circular drum that connects to the inlet port sleeve. Strain gauges were installed on the critical locations on the geotextile test specimen both on body and inlet port sleeve. Several types of inlet port designs were tested, and the critical tearing strength of these inlet ports were analysed. Test results suggest that the seam design connecting the inlet sleeve and geotextile body is a key factor in deciding the critical tearing strength of an inlet port design.

Research studies have revealed that people with hoarding typically collect and keep items due to their aesthetic appeal, utility and strong emotional attachment to the items resulting in clutter and limiting living spaces. This study aims to explore the experiences of individuals with hoarding disorder to understand and describe—the patterns and reasons for hoarding, experiences with decluttering and the impact of hoarding disorder on significant others and society in the context of a multi‐ethnic urban Asian country. A total of 12 participants with hoarding disorder were recruited and interviewed using a simple semi‐structured interview guide designed for the study. The resulting transcribed interviews were analysed using thematic analysis. The mean age of the participants was 56.7 years (SD = 14.5). Nine super‐ordinate and discrete but interconnecting themes emerged from the qualitative interviews: types of hoarded items, sources of hoarded items, ways of storing/arranging hoarded items, help‐seeking/treatment contact, reasons for hoarding, experiences with decluttering, impact upon family, community and self, restricting hoarding behaviours and insight. Key themes identified in the study are consistent with the literature on studies on hoarding which have been done in other populations. Hoarding in the community has serious consequences for individuals with hoarding disorder and others living in the community, which is compounded by the lack of insight among these individuals. There is a pressing need to increase public awareness and recognition of hoarding behaviours to aid efforts in bringing timely and appropriate services to the affected individuals.

The Housing and Development Board (HDB) houses over 80% of the population of Singapore in one million flats spread over 23 towns. In recent years, the HDB has intensified its building programme to meet the housing demand in Singapore. As the city’s heartlands develop into high-density townships, urban greenery has become an integral part of the urban fabric, playing an indispensable role in mitigating the high densities and ensuring a quality living environment. The essay discusses how the development of HDB towns is guided by comprehensive principles, which consider greenery at both the macro- and micro-scales, from the planning and urban design of towns to the design and implementation of individual precincts and buildings.

The traditional modification factor approach employed to evaluate the building movements due to tunneling is for plane-strain situation. Such approach could not cater for the effect of building dimension along the tunnel axis. In the present study, three-dimensional finite element analyses were conducted to determine the movements of buildings with various plan dimensions and locations induced by tunneling. A new modification factor is proposed to cater for the true three-dimensional nature of the problem. A relationship between the new modification factor and building bending stiffness is proposed to determine the relative movement between the shallow foundation and Greenfield ground settlement due to tunneling.

This research aims to understand the demand for sustainable buildings by investigating the tenant organizations' willingness-to-pay (WTP) behavior towards the value-added benefits (VABs). Tenant organizations refer to tenants operating in office buildings on tenancy agreement. Six groups of factors of tenant organizations' WTP for the VABs are identified: (1) Organization Characteristics, (2) Current Premises, (3) Building Characteristics, (4) Satisfaction of the VABs Experienced, (5) Perception, and (6) Knowledge of Sustainability Issues, Building Sustainability Rating Systems and Building Impacts. A survey was conducted on the tenant organizations operating in office buildings located in the city area of Singapore. The hypothesized relationship between the tenant organizations' WTP for the VABs and its factors were tested using a series of statistical techniques on the data collected from the survey. It is found that older tenant organizations tend to have lower WTP for the VABs of improved health and comfort of their employees. Generally, tenant organizations also have demand for sustainable buildings mainly due to the positive organizational image that sustainable buildings help to project. In addition, it is found that the current building sustainability rating systems are inadequate for communicating the sustainability benefits to building occupants and for achieving building sustainability. Lastly, the investigation reveals that the use of sustainable technologies is not as important as how the building is being managed during its operational stage for ensuring building sustainability performance. The findings from this study are useful for channeling the sustainability efforts of the building industry to more effective areas.

A large-scale lifetime building monitoring program was implemented in Singapore in 2001. The monitoring aims of this unique program were to increase safety, verify performance, control quality, increase knowledge, optimize maintenance costs, and evaluate the condition of the structures after a hazardous event. The first instrumented building, which has now been monitored for more than ten years, is presented in this paper. The long-gauge fiber optic strain sensors were embedded in fresh concrete of ground-level columns, thus the monitoring started at the birth of both the construction material and the structure. Measurement sessions were performed during construction, upon completion of each new story and the roof, and after the construction, i.e., in-service. Based on results it was possible to follow and evaluate long-term behavior of the building through every stage of its life. The results of monitoring were analyzed at a local (column) and global (building) level. Over-dimensioning of one column was identified. Differential settlement of foundations was detected, localized, and its magnitude estimated. Post-tremor analysis was performed. Real long-term behavior of concrete columns was assessed. Finally, the long-term performance of the monitoring system was evaluated. The researched monitoring method, monitoring system, rich results gathered over approximately ten years, data analysis algorithms, and the conclusions on the structural behavior and health condition of the building based on monitoring are presented in this paper.

Two laboratory flume experiments on the effect of surface rock fragments on precipitation‐driven soil erosion yields were carried out. The total sediment concentration, the concentration of seven individual size classes, and the flow discharge were measured. Digital terrain models (DTMs) were generated before and after one of the experiments. The results revealed that the rock fragments protected the soils from raindrop detachment and retarded the overland flow, therefore decreasing its sediment transport capacity. Rock fragments were found to affect selectively the different size classes in a manner that changed according to the time scale. For short times, the rock fragment coverage reduced erosion of the finer particles (<20 μm). For the midsize classes the protection decreased, while erosion of the larger size classes (>100 μm) was unaffected. At long times the rock fragment cover decreased the concentration of the individual size classes in proportion to effective rainfall intensity and the area exposed to raindrops. An area‐based modification of the Hairsine and Rose (H‐R) soil erosion model was employed to analyze the experimental data. The H‐R model predictions agreed well with the measured sediment concentrations when high rainfall intensity and low rock fragment cover were used. Predictions were instead less accurate with low rainfall intensity and high rock fragment cover. The DTM results showed that the presence of rock fragments on the soil surface led to increased soil compaction, perhaps due to higher soil moisture content (from greater infiltration) within the rock fragment‐covered flumes.