Underground space planning in Helsinki

This paper gives insight into the use of underground space in Helsinki,Finland.The city has an underground master plan(UMP) for its whole municipal area,not only for certain parts of the city.Further,the decision-making history of the UMP is described step-by-step.Some examples of underground space use in other cities are also given.The focus of this paper is on the sustainability issues related to urban underground space use,including its contribution to an environmentally sustainable and aesthetically acceptable landscape,anticipated structural longevity and maintaining the opportunity for urban development by future generations.Underground planning enhances overall safety and economy efficiency.The need for underground space use in city areas has grown rapidly since the 21 st century;at the same time,the necessity to control construction work has also increased.The UMP of Helsinki reserves designated space for public and private utilities in various underground areas of bedrock over the long term.The plan also provides the framework for managing and controlling the city’s underground construction work and allows suitable locations to be allocated for underground facilities.Tampere,the third most populated city in Finland and the biggest inland city in the Nordic countries,is also a good example of a city that is taking steps to utilise underground resources.Oulu,the capital city of northern Finland,has also started to ‘go underground’.An example of the possibility to combine two cities by an 80-km subsea tunnel is also discussed.A new fixed link would generate huge potential for the capital areas of Finland and Estonia to become a real Helsinki-Tallinn twin city.

Building 3D Cadastral System Based on 2D Survey Plans with SketchUp

Three-dimensional (3D) land development and utilization has become the trend for urban planning in the current metropolis.This paper presents a method for building a 3D cadastral management system from survey plans with SketchUp.It concentrates on the geometric representation and topological consistent maintenance of 3D cadastral objects.In this system a complete topological model is built to express the body construction and spatial relationships among 3D property units.SketchUp is used to automatically construct 3D models with attributes and thematic information from 2D survey plans.Spatial topologic relationships and operations are analyzed with the programming and development of Ruby language.The resulting system can manage 3D cadastral objects and manipulate them with spatial operations to support spatial analysis.

Design and development of a web-based 3D cadastral visualisation prototype

Three-dimensional(3D)developments of land,such as complex high-rises,put enormous pressure on current land administration systems that have ad hoc approaches to 3D property management.These approaches are unable to support effective 3D storage,analysis and visualisation of property information.Effective visualisation is one of the essential components in realisation of a truly 3D cadastre.Currently,several 3D visualisation applications and cadastral prototypes have been developed around the world.However,they do not effectively represent ownership information in 3D because they have not been developed based on 3D cadastral visualisation requirements.After candidate 3D visualisation solutions were compared with user-derived visualisation criteria,a web-based 3D visualisation prototype was designed and developed.The functionality,usability and efficiency of the prototype were evaluated by potential users involved in the registration and management of property.While there was a high level of enthusiasm for the features of the prototype,the results also suggest further directions for development of 3D cadastral visualisation.

Exploring the applications of 3D proximity analysis in a 3D digital cadastre

Increasing population in urban areas and limitations of suitable lands for developing houses and urban infrastructure have led to the vertical development in cities.However,these developments are managed by a cadastral system which is mainly two-dimensional and cannot efficiently represent Rights,Restrictions,and Responsibilities(RRRs)in complex scenarios.In fact,a three-dimensional cadastre is required for efficiently registering and representing RRRs.In this paper,a 3D proximity analysis was proposed and implemented to determine RRRs and associated easement rights in non-topology-based data structures.This method can be used to investigate the surrounding spaces of a subject apartment unit or storage in a high-rise.The performance of the developed method was evaluated in a large complex high-rise in Tehran,Iran.The results confirmed that the proposed method can correctly identify the neighbor spaces in complex scenarios.

Integration of cadastral survey data into building information models

Cadastral surveying plays an important role in defining legal boundaries of land and property.The current practice for recording cadastral survey data mainly relies on 2D digital or analog documents.This practice is efficient for simple land parcels but can be challenged in complex building developments.To address the issues stemmed from 2D methods of representing cadastral survey data,3D spatial information models can be considered as a viable solution for managing cadastral survey data.Building Information Modeling(BIM)enables colsslaborative 3D management of the design,construction,and operation of buildings.There have been extensive studies conducted to investigate the connectivity between BIM and 3D cadaster.Most of these studies focus on managing legal information,such as ownership boundaries and attributes,in BIM-based environments.However,there is limited investigation on how survey-ing measurements can be mapped into BIM.In this study,the proposed method for integrating the cadastral survey data into the BIM environment includes identifying cadastral survey requirements,using BIM entities relevant to cadastral survey data,enrichment of a BIM proto-type,and evaluation of the prototype.The major contribution of this study is to demonstrate the storage of cadastral survey data such as survey marks and traverse lines in the BIM environment.Therefore,this research contributes to the further enrichment of BIM with incorporating data elements related to cadastral surveying practices.It is confirmed that current BIM-based tools provide restricted capabilities for explicit management and visualiza-tion of cadastral survey data.This limitation can be addressed in the future enhancements of BIM in terms of supporting important elements for cadastral survey data.