翻译原文Interactive 3D CAD for Effective Derrick Crane Operation in a Cable-Stayed Bridge Constructio_to.pdf

CASE STUDIES Interactive 3D CAD for Effective Derrick Crane Operation in a Cable Stayed Bridge Construction Taekwun Park1 Moon Kyum Kim2 Changyoon Kim3 and Hyoungkwan Kim4 Abstract The high expectation of esthetic and functional quality in modern civil infrastructure has resulted in the increased demand for long span bridges In advanced or developing countries long span bridges such as cable stayed and suspension bridges are considered even as landmarks that symbolize the prosperity or culture of the region These long span bridges require higher level of design and construction technologies than other types of bridges In particular the construction of cable stayed bridges involves precise and sophis ticated operation of construction equipment such as derrick cranes However it is not easy to plan the operations of a derrick crane before the actual construction process takes place Unexpected spatial constraints in the construction site may hinder the smooth operation of a derrick crane which leads to lower than expected productivity and safety This study applies interactive three dimensional 3D computer aided design CAD to the derrick crane operation for the purpose of identifying potential problems Construction managers can have the two way process with the 3D CAD system to interactively test their construction plans and scenarios The case study shows that the interactive 3D CAD system signifi cantly improves the constructability of the cable stayed bridge construction DOI 10 1061 ASCE CO 1943 7862 0000101 CE Database subject headings Bridge construction Cable stayed Bridges Computer aided drafting Construction equipment Cranes Introduction The high expectation of esthetic and functional quality in modern civil infrastructure has resulted in the increased demand for long span bridges Long span bridges such as cable stayed and suspen sion bridges are considered even as landmarks that symbolize the prosperity or culture of the region In particular cable stayed bridges have recently gained increasing popularity due to the ever improving record of the total span length between pylons along with suffi cient structural stability and economy There are generally two types of construction methods for cable stayed bridges in terms of installing deck segments between pylons One is using temporary bents and the other is the canti lever method Temporary bents as shown in Fig 1 a are the structures that support the deck during the construction The bents are removed after all the cables are connected to the deck seg ments In contrast the cantilever method Fig 1 b makes use of derrick cranes to gradually extend the deck A derrick crane is a simple type of crane composed of boom and wire A derrick crane positioned on a preinstalled segment places the new segment as a cantilever This process is repeated until all the segments are in stalled The cantilever method is more widely used than the tem porary bent approach because it can be economically used irrespective of the topographical conditions The unique nature of a civil engineering project tends to re quire construction methods customized for the specifi c project Many cable stayed bridge constructions using the cantilever method are not an exception For example to construct a cable stayed bridge inland a special kind of derrick crane should be designed to install various structural members However when this unique equipment is used in the one of a kind construction site the constructability is at stake Analyses had better be con ducted in advance to identify spatial constraints related to the operation of the derrick crane Literature Review and Research Objective Efforts have been made to accurately model a range of construc tion processes in the area of three dimensional 3D computer aided design CAD When 3D CAD is combined with time or additional information the concept of four dimensional 4D or nD n dimensional CAD is formed Here since the 4D or nD concept is an extension of 3D CAD they are also included in the literature review of 3D CAD application for construction process analyses 3D CAD technology can be roughly classifi ed into two catego ries activity level and operation level 3D CAD on an activity 1Senior Manager Daelim Industrial Corp Seoul 110 732 Korea E mail tkpark daelim co kr 2Professor Dept of Civil and Environmental Engineering Yonsei Univ Seoul 120 749 Korea E mail applymkk yonsei ac kr 3Graduate Research Assistant School of Civil and Environmental En gineering Yonsei Univ Seoul 120 749 Korea E mail changyoonkim yonsei ac kr 4Associate Professor School of Civil and Environmental Engineering Yonsei Univ Seoul 120 749 Korea corresponding author E mail hyoungkwan yonsei ac kr Note This manuscript was submitted on February 15 2009 approved on May 26 2009 published online on May 29 2009 Discussion period open until April 1 2010 separate discussions must be submitted for individual papers This paper is part of the Journal of Construction Engineering and Management Vol 135 No 11 November 1 2009 ASCE ISSN 0733 9364 2009 11 1261 1270 25 00 JOURNAL OF CONSTRUCTION ENGINEERING AND MANAGEMENT ASCE NOVEMBER 2009 1261 Downloaded 24 Jul 2010 to 220 168 30 6 Redistribution subject to ASCE license or copyright Visit http www ascelibrary org level is to represent structural or mechanical components that are tied with the planning unit of activity whereas the operation level is more detailed enough to show the actual construction operation including the movement of equipment and materials There are some representative research in the activity level 3D CAD Koo and Fisher 2000 created a 4D CAD model for a commercial construction project to evaluate the usefulness of 4D CAD Staub French et al 2008 developed a method to associate 3D CAD with linear scheduling To improve construction safety Akinci et al 2002 provided a way to automatically estimate 3D work space requirements dictated by construction activities The operation level 3D CAD requires more in depth knowl edge of the construction operations Al Hussein et al 2006 de veloped a methodology to visualize construction simulation results Tower crane operations were animated to help project managers better understand the detailed level of construction op erations Manrique et al 2007 presented a methodology to build a complex residential tilt up panel The operation level animation was to experiment with the planned construction process to re duce on site errors as much as possible Mixed augmented reality forms another category of 3D CAD application By combining 3D computer graphic models with real image of the construction site users can have an improved under standing of what should be designed or built Dunston and Wang 2005 presented mixed reality based computer interfaces for con struction projects Kamat and El Tawil 2007 applied augmented reality to the rapid assessment of earthquake induced building damage Behzadan and Kamat 2007 investigated how to accu rately align real world objects with virtual 3D CAD objects to effectively create augmented reality These previous studies have pioneered the way that the con struction activities or operations are modeled and analyzed How ever these research efforts have been too much focused on either architectural engineering Koo and Fisher 2000 Akinci et al 2002 Staub French 2008 Manrique et al 2007 Al Hussein et al 2006 Kale and Arditi 2005 Kamat and El Tawil 2007 or plants construction Dunston and Wang 2005 Although Behzadan and Kamat 2007 used a bridge construction case they were mainly concerned about the issue of how to register virtual construction objects in the system of augmented reality Civil engineering con struction such as cable stayed bridges due to its complex struc tures deserves a thorough analysis of spatial constraints such that any potential spatial problems can easily be detected and cor rected In this study an interactive 3D CAD system is proposed to predict potential problems in cable stayed bridge constructions This system is based on the object oriented concept Each 3D component can represent distinguishable geometric properties as well as material and other properties With the system users can interactively test a range of construction plans and scenarios as they arise For example an issue of where to unload construction materials or where to position a piece of construction equipment can be easily resolved by visualizing the idea through the 3D CAD system Collision between structural components is also easily checked The system was applied to a real construction project a cable stayed bridge construction focusing on the op eration of the derrick crane Based on the case study the capa bilities and limitations of the system are presented Object Oriented Interactive 3D CAD The most important precondition for the interactive 3D construc tion plan examination is to have the required 3D component mod els prepared in advance The 3D model development starts with the careful scrutiny of the existing two dimensional 2D draw ings and specifi cations Revit Architecture 2008 produced by Au todesk Inc was used as the platform on which to create the 3D model Based on the function location and the required manage ment level of detail each 3D object is fi rst defi ned and modeled To begin with a mass template 3D shape that is similar to the real component is chosen and the template is step by step modi fi ed to match the exact shape of the real component Two or more objects can be joined a certain shape of void can be created inside of the object and a 2D profi le can revolve to create the 3D object In case of an architectural engineering structure many predefi ned templates such as walls and fl oors exist However in civil engineering structures such as the one in this study almost all the 3D components needed to model the site have to be created from such basic shapes For example the complex construction components such as edge girders stringers and fl oor beams are generated by combining basic shapes rectangular boxes and cyl inders Once created the 3D objects are stored in the library of the system to be reused wherever a new component with similar shape needs to be modeled For example a parametric modeling Fig 1 Different deck construction methods a temporary bent b cantilever method 1262 JOURNAL OF CONSTRUCTION ENGINEERING AND MANAGEMENT ASCE NOVEMBER 2009 Downloaded 24 Jul 2010 to 220 168 30 6 Redistribution subject to ASCE license or copyright Visit http www ascelibrary org concept was used to generate precast concrete panels based on the original template in this study The 3D objects created are given their proper names material information etc thanks to their object oriented characteristics As aforementioned from the creation of objects to their storage and to reuse instead of line or area the independent 3D objects are used This feature enables users to depict the construction site more clearly especially in the case of construction scenario analyses For example when construction engineers want to check if there is enough space for edge girders to be unloaded in the place right next to the derrick crane construction engineers can simply choose the edge girder objects and put them next to the crane object for the virtual testing If the construction engi neers this time want to put fl oor beams right next to the edge girders they can try so in the 3D environment too This interac tive process is allowed since the real structural members and equipment are modeled based on the true object oriented concept Construction equipment and temporary structures such as the derrick crane a trailer man cages and working platforms are modeled separately and later imported to the main platform of the bridge construction scenario Their placement on any location in the interactive CAD system is tantamount to experimenting with a mixture of construction plans that are in reality hard to be tested Case Study The interactive 3D CAD system was applied to the Cheongpoong Grand Bridge a cable stayed bridge being constructed in Jechon Chungcheongbuk do Korea The total length of the bridge was designed to be 442 m with the center span between two pylons and each side span being 327 and 57 5 m respec tively This bridge will provide a new transportation connection between Mooltae li and Dowha li over the Cheongpoong Lake In a typical offshore construction of a cable stayed bridge deck segments are prefabricated and delivered by barges to the site Then the derrick crane on the preinstalled deck lifts each new segment up to the proper level in order to install it as the cantilever This prefabrication approach is quite effective where barges can have good access to the site e g offshore construc tion However a majority of inland construction of cable stayed bridges does not allow for the approach due to the barge access and other technical or economic diffi culties This is the case of the Cheongpoong Grand Bridge therefore construction engineers in volved in the project decided to assemble each deck segment on site by installing structural members one by one The original idea was to use a general type of crawler crane with the dead load of 100 t However the engineers soon discov ered that the crawler crane was too heavy even with its own weight Therefore a special kind of derrick crane with just 70 t was designed just for this project Fig 2 Unlike other derrick cranes used for deck segment installation the derrick crane in this project is positioned not on the center but on one side of the deck from the perspective of transportation direction This is to secure a suffi cient level of empty space on the other side through which a range of construction materials can be moved As shown in Fig 2 the crane has a rectangular base to be more mechanically stable than a triangular shape A mast is placed on a corner of the base and the boom can rotate about the mast with different vertical angles The center span of the Cheongpoong bridge is composed of 28 deck segments with 14 segments on each side A derrick crane with the above mentioned features is used for each side to install the 14 segments in the order of side to center starting from the one that is closest to the pylon and fi nishing with the one in the center On each side the process of installing the fi rst segment is repeated 14 times to fi nish the deck construction Therefore con struction engineers put utmost importance on the 3D modeling of the fi rst segment to predict potential construction problems The deck segment installation process is composed of the following tasks 1 As a precondition the concrete deck of the side span is com pleted and two steel joints are connected to the concrete deck A rail is installed on the deck of the side span so as to easily move the derrick crane 2 Move the derrick crane forward to the right position and anchor the crane to the lugs that are preinstalled Fig 3 3 Edge girders are moved and installed Fig 4 4 Man cages are placed for the bolting of the edge girders to the steel joints Fig 5 5 Man cages are removed 6 A safety net is installed using the two edge girders for the protection of the workers 7 Floor beams are moved and installed Fig 6 8 Stringers are moved and installed Fig 7 Fig 2 Derrick crane for Cheongpoong Grand Bridge Fig 3 Derrick crane setting JOURNAL OF CONSTRUCTION ENGINEERING AND MANAGEMENT ASCE NOVEMBER 2009 1263 Downloaded 24 Jul 2010 to 220 168 30 6 Redistribution subject to ASCE license or copyright Visit http www ascelibrary org Fig 4 Edge girder installation a left side b right side Fig 5 Man cage Fig 6 Floor beam installation Fig 7 Stringer installation a three stringers joined together b stringer being bolted 1264 JOURNAL OF CONSTRUCTION ENGINEERING AND MANAGEMENT ASCE NOVEMBER 2009 Downloaded 24 Jul 2010 to 220 168 30 6 Redistribution subject to ASCE license or copyright Visit http www ascelibrary org 9 Working platforms are moved and placed and using the plat forms construction workers hang and partially stress cables Swiggum et al 1994 Fig 8 10 The working platforms are removed 11 Six precast concrete panels are one by one moved and in stalled Fig 9 12 Cast in place concrete are used to join the precast concrete panels with each other and to the steel structural members edge girders fl oor beams and stringers resulting in the formation of a deck segment Fig 10 13 After three days of concrete curing the cables are partially stressed again for the adjustment to the newly formed deck segment 14 The rail is extended The rail is composed of two pieces front part and back part To extend the rail the back part is detached from the deck and installed as the new front part the original front part becomes the back part In this way the rail can move forward continually 15 The steps from 2 to 14 are repeated until the fi nish of the deck construction Collision Check of Structural Members One of the most important functions of 3D CAD is undoubtedly collision check of structural members With the traditional 2D drawings it is diffi cult to visualize the completed status of the facility to be built This is only truer with the ever increasing size and complexity of civil engineering infrastructure However 3D CAD allows for an opportunity to ensure that this collision prob lem is resolved before the actual construction starts More than 100 pages of 2D drawings existed only for the superstructure of the Cheongpoong bridge They can be classifi ed into many categories by locations materials view and the level of detail Some examples of locations are upper part lower part side span and center span Materials include steel structural members reinforcing bars and cast in place concrete Plan side and cross sectional views are also used with different levels of detail to accurately represent specifi c structural objects For con struction engineers to understand the structure to be built the versatile information should be well combined to create the 3D v