Extending a BIM-based data model to support 3D digital management of complex ownership spaces

Currently, 2D-based analogue building subdivision plans are used to represent the spatial extent of private, public and communal property ownership rights. These plans are recognized as posing a range of challenges in terms of communicating the spatial complexity of ownership spaces within multi-storey buildings. In response to these challenges, three-dimensional (3D) digital data environments are being investigated as a potential approach for managing complex, vertically stratified ownership arrangements. The argument presented in this article is that Building Information Modelling (BIM) can be adopted for 3D digital management of data related to complex ownership spaces. BIM provides a common and 3D digital data sharing space, underpinning a reliable basis for facilitating collaboration and decision-making over the lifecycle of buildings. However, ownership attributes and the spatial structure of ownership arrangements inside buildings are yet to be accommodated within the BIM data environment. In this article, we present a range of required data elements for managing complex ownership spaces, which have been elicited by investigating current practices pertaining to subdivision of ownership spaces within multi-storey buildings in Melbourne, Australia. An open data model in the BIM domain is extended with these data elements and a prototype model for a real multi-storey building is implemented to demonstrate the viability of the extended data model for 3D digital management and visualization of data related to complex ownership arrangements.     

Assessment of Sulfate Concentrations in Water Used During Chemical Stabilization and Its Potential Impact on Sulfate Induced Heave

The occurrence of sulfate-induced heave of roadways that were chemically stabilized with either lime or cement can require expensive road repairs. Previous research attributed the heave to the formation of an expansive mineral named ettringite. However, not all chemically stabilized soils will exhibit heave. The overall goal of this research was to determine if the sulfate concentration in water can contribute to, or even cause, sulfate induced heave. Two soils, one with a soluble sulfate level below 3000 mg/kg and one with >8000 mg/kg sulfate, were stabilized with either lime or cement and subjected to a capillary soak with distilled water or saturated sulfate water. The low sulfate soils did not swell above the accepted limit of 1.5 %. The high sulfate soils swelled significantly (p < 0.05) above accepted level regardless of the stabilizer used. Overall, stabilized soils subjected to a capillary soak with saturated sulfate water swelled more than soils soaked with distilled water. The results found in this study demonstrated that cement will increase the axial load capacity of the soil, but the soil will still have the potential to heave excessively if sulfate and aluminum are present above the stoichiometric requirements to from ettringite.     

A Simple Limit Equilibrium Approach for Calculation of Ultimate Bearing Capacity of Shallow Foundations on Two-Layered Granular Soils

The bearing capacity of shallow foundations in a non-homogeneous soil profile has been a challenging task in geotechnical engineering. In this paper, a limit equilibrium method is used for calculating bearing capacity factors of shallow foundations constructed on a two-layered granular soil profile. The main objective has been to determine the ultimate bearing capacity computed from equivalent bearing capacity factors N_q and N_γ and comparing that with numerical analysis using finite element methods. It will be shown that the data obtained form the developed method are well comparable with those obtained from FE approach, specially when the difference between shear strength parameters of layers is low which is a practical case for sedimentary soil profiles and also for artificially compacted soils. A computer program has been developed to investigate the influence of various parameters on bearing capacity factors.     

Gorgan Bay:a microcosm for study on macrobenthos species-environment relationships in the southeastern Caspian Sea

The relationship between spatial patterns of macrobenthos community characteristics and environmental conditions(salinity, temperature, dissolved oxygen, organic matter content, sand, silt and clay) was investigated throughout the Gorgan Bay in June 2010. Principal components analysis(PCA) based on environmental data separated eastern and western stations. The maximum(4500 ind./m²) and minimum(411 ind./m²) densities were observed at Stas 1 and 6, respectively. Polychaeta was the major group and Streblospio gynobranchiata was dominant species in the bay. According to Distance Based Linear Models results, macrofaunal total density was correlated with silt percentage and salinity and these two factors explaining 64% of the variability while macrofaunal community structure just correlated with salinity(22% total variation). In general, western part of the bay showed the highest number of species and biodiversity while, the highest density was found at Sta. 1 and in the middle part of the bay. Furthermore, relationship between diversity indices and macrobenthic species with measured factors is also discussed. Our results confirm the effect of salinity as an important factor on distribution of macrobenthic fauna in south Caspian brackish waters.     

An investigation of the effects of important grouting and rock parameters on the grouting process

Today, grouting is used as an aid in ground improvement in most civil and mining engineering projects. Groutability and grout penetration depth are among the most important issues that are considered in grouting operation. Various parameters such as in-situ stress, pore water pressure, joint geometric and geomechanical characteristics, grout properties (viscosity and yield stress) and technical factors such as grouting pressure and flow rate affect the groutability and grout penetration depth in a jointed rock mass. Knowledge of the effect of these parameters has advantages in the prediction of grouting results. Typically, cement-based grout is used in jointed rock masses. Unlike water, stable cement-based grout usually acts as a Bingham fluid. In this study the effect of important parameters on grouting process in a jointed rock mass was investigated numerically using the DEM method. In the conducted study, the problem geometry represents a horizontal section in a regularly jointed rock mass with two joint sets. The analyses results show that the grout penetration depth and intake increase as joint aperture, normal stiffness and grouting pressure increase and in-situ stress and pore water pressure decrease. Increase in joint spacing does not have any effect on the grout penetration depth but decreases the grout intake. The effect of joint orientation on grouting process is strongly dependent on in-situ stress state. On the other hand, increase in grout yield stress decreases the grout penetration depth and intake, while grout viscosity does not have any effect on maximum grout penetration depth and intake. To further investigate the above mechanisms, the grouting process conducted in Gotvand dam-Iran was simulated numerically.     

Permian Calcareous algae from the Khachik Formation at the Ali Bashi Mountains,NW of Iran

Micropaleontological investigations on Permian successions in the NW of Iran based on algae led to the determination of taxa belonging to some families such as Ungdarellaceae (Ungdarella uralica), Gymnocodiaceae (Gymnocodium bellerophontis and Permocalculus sp.), Dasycladales (Mizzia cf. M. yabei), and some microproblematics (Vermiporella nipponica and Pseudovermiporella sodalica). These investigations are mainly focused on the Khachik Formation at the Ali Bashi Mountains. According to the algal community, a lagoon environment is offered for the studied successions.