DECEMBER 15, 2014 PROPOSAL BRIAN BERNENS THE APARTMENT BUILDING ROCKVILLE, MD

Transcription

1 DECEMBER 15, 2014 PROPOSAL BRIAN BERNENS THE APARTMENT BUILDING ROCKVILLE, MD

2 EXECUTIVE SUMMARY The following proposal details the ideas and opportunities for improved construction processes in the Apartment Building. Included are 4 analyses, 2 option breadths, and a schedule for the work to be performed in the spring semester of There is a focus on schedule, so the building can be turned over to the owner for apartment rentals, as well as constructability and costs. Below are descriptions for the 4 analyses: application of linear scheduling of interior trades, modification of residential structure, research of 3D construction visualization, and the addition of a tower crane. Analysis 1: Linear Scheduling of Interior Trades An analysis of the interior trade sequencing will be performed to see how the schedule can be accelerated. This analysis will intend to use simultaneous crews in building 100 and 200 to increase production as well as creating a linear schedule to better maintain the work flow of the trades. This analysis will provide opportunity for an acoustical breadth. Analysis 2: Timber Structure Modification Analysis 2 will evaluate using an alternate structural system, called an Infinity structural system, replacing the current timber framed residential portion of the Apartment Building. The Infinity structure is a prefabricated metal stud, metal deck, and concrete slab system that will benefit the Apartment Building in life cycle costs and quality of construction. This analysis will provide an opportunity for a structural and acoustical breadth. Analysis 3: Critical Industry Issue - 3D Modeling Research of a critical industry issue on the topic of BIM and 3D visualizations will be presented in Analysis 3. The open source software VITASCOPE, created by Dr. Vineet R. Kamat, will be researched for the use on the Apartment Building and to understand how 3D visualizations of construction processes can benefit all types of projects. This analysis will be coupled with analysis 4 to create a visualization of tower crane work flow. Analysis 4: Site Logistics Alterations This analysis will study how the addition of a tower crane to the site can improve the construction of the cast-in-place podium structure. The current use of hydraulic cranes will be evaluated with the increased production and costs of operating a tower crane and suggestions will be made to the contractor and owner. A structural breadth opportunity will present itself in the form of designing the tower crane foundation. 12/15/2014 Proposal Page a

3 CONTENTS Executive Summary... a Project Background... 1 Analysis 1: Linear Scheduling of Interior Trades... 2 Problem Identification... 2 Background Research... 2 Potential Solution... 3 Methodology and Resources... 3 Expected Outcome... 4 Analysis 2: Timber Structure Modification... 5 Problem Identification... 5 Background Research... 5 Potential Solution... 5 Methodology and Resources... 6 Expected Outcome... 6 Analysis 3: Critical Industry Issue - 3D Modeling... 7 Problem Identification... 7 Background Research... 7 Methodology and Resources... 7 Goal of Research... 8 Analysis 4: Site Logistics Alterations... 9 Opportunity Identification... 9 Background Research... 9 Potential Solution... 9 Methodology and Resources...10 Expected Outcome...10 Conclusions...12 Overall Weighting Breakdown...12 Appendix A...13 Breadth Studies...14 Structural Breadth...14 Acoustical Breadth...14 Appendix B...15 Spring Analysis Schedule...16

4 PROJECT BACKGROUND The Apartment Building is a mixed use, 5- story building located in Rockville, MD. The project is broken into 3 buildings: 100, 200, and 300. The first story (bldg. 100 and 200) consists of a 22 concrete podium and will serve as 33,000 SF of future retail space. The above 4 floors are timber framed and will be utilized as 170,000 SF of 206 apartment units. Building 300 is a precast parking garage serving 465 parking spots. The project is approximately $34M and will be completed in 22 months. The Apartment Building will be targeting a gold status in the LEED for Homes rating system. Because of the nature of apartments, the owner places the schedule at the highest importance so that the units may be rented as soon as possible. Courtesy of James G. Davis Construction BLDG 200 BLDG 300 BLDG 100 Figure 1: Location of buildings on site 12/15/2014 Project Background Page 1

5 ANALYSIS 1: LINEAR SCHEDULING OF INTERIOR TRADES PROBLEM IDENTIFICATION The Apartment Building s interior finishes schedule for the 206 apartment units currently flows from south to north, floor by floor, with work beginning in building 100 and then moving onto building 200 once 100 has finished. Each floor has an average duration of 98 days. If delays occur in preceding activities, the project will be delayed due to the interior finishes being a predecessor for final inspections and turnover of the buildings. Currently, MEP Rough-Ins have been delayed on the project, so the project team has had the challenge of making up the lost time. Because this building is hosting apartment units, the owner is eager to have the building turned over as fast as possible. BACKGROUND RESEARCH In order to avoid delays and/or accelerate the schedule, the method of Linear Scheduling will be analyzed to see how it can be applied to the Apartment Building to increase the production and work flow of the interior trades. The Apartment Building utilizes a standard CPM bar chart for the project schedule. While a bar or Gantt chart is the most standard schedule type used in construction, there are disadvantages such as the inability to immediately realize the effects of changes in activity sequences and/or durations. Issues can also arise with CPM schedules on repetitious projects because the schedule can become too detailed and this can cause confusion in the field amongst personnel not trained in the methodologies of CPM scheduling. The Linear Scheduling Method (LSM) is used for repetitive projects and repetitive elements, such as housing, high-rises, road construction, and building finishes. A LSM schedule can provide a simple graphical representation of productivity that can be easily read in the field. Because linear scheduling integrates resources and logic, LSM schedules are useful for the project team to easily interpret, suggest changes, implement these changes, and overall LSM schedules are complements to CPM schedules. Linear schedules are represented by two axes: distance and time. Schedule activities are plotted as lines with a designated slope that represents the production rate of the activity. Adjustments to the slope can be made if/when an activity works at a slower or different rate. The resources must be balanced with one critical trade to act as the critical path item and so the schedule is resource restrained to push the overall schedule. 12/15/2014 Analysis 1 Page 2

6 POTENTIAL SOLUTION This analysis will look into using two live crews, working simultaneously in building 100 and 200, to accelerate the schedule. The production rates can be compared back to the original, actual crew rates to identify a schedule opportunity. This analysis will evaluate the current CPM schedule for finishes and create a linear production schedule to show the production of the interior finishes. Since there are many interior finish trades, a focal point of the finishes will need to be selected that can represent the entire sequence of interior finishes. METHODOLOGY Research and identify best method of linear scheduling application for finishes: sequence, parallel, or flowline Identify the interior finishes trade(s) that will be most useful to study for this analysis Obtain information on current crews and production rates for hanging drywall to compare analysis results with Calculate schedule durations and project completion date with obtained current crew production rates Create linear schedule optimizing drywall crews and accelerating schedule Evaluate schedule savings of operating crews in both building 100 and 200 at the same time Estimate additional labor costs of operating crews in both building 100 and 200 at the same times RESOURCES Application of Linear Scheduling by Edmund N. Chrzanowski Chapter 8, Managing the Construction Process by Frederick E. Gould RS Means AE 476 notes on Linear Scheduling by Dr. Rob Leicht 12/15/2014 Analysis 1 Page 3

7 EXPECTED OUTCOME This analysis will be able to identify an opportunity to accelerate the schedule as well as ensuring that the project completion date is not pushed back by operating simultaneous finishes crews in both building 100 and 200. Through the linear scheduling method, it is expected that productivity and work flow will be optimized as well as easily measured for the entire project team. Because the interior finishes will be examined closely, an opportunity for an acoustical breadth will be available while analyzing how the finishes will affect the sound insulation of a typical apartment unit. 12/15/2014 Analysis 1 Page 4

8 ANALYSIS 2: TIMBER STRUCTURE MODIFICATION PROBLEM IDENTIFICATION The Apartment Building features 4 floors of apartments, totaling 206 units, all of which are supported by a timber frame. While timber framing is a popular and upfront cost-effective building material, it has some downfalls. First, wood is extremely combustible and so extra care must be taken to protect the structure from spread of fire (the Apartment Building has a large masonry fire wall that divides building 100 and 200). Moisture can easily be absorbed during the construction process if not stored correctly which can lead to decay of structural members while termites can cause structural problems with wood. Because of these two issues, wood does not sustain its life as long as other building materials such as steel or concrete. Timber framing requires experienced crews to erect properly and can lead to a loss of structural integrity if not installed properly. In regards to future renovations, timber framing does not offer much, as removing a small section would compromise the stability of the entire structure. Overall there are many disadvantages that outweigh the low upfront cost of a timber framed structure. BACKGROUND RESEARCH To combat the disadvantages of the Apartment Building s timber structure, an alternative system will be analyzed called the Infinity Structural System. The Infinity Structural System consists of prefabricated load bearing metal stud walls, high performance metal deck, and a concrete slab. The system has most often been used in mid-rise buildings such as apartments, student housing, and hotels. When compared to a wood structure, there are many advantages. The Infinity system s stud walls are prefabricated offsite which enables a fast installation onsite. Unlike wood, there will be no problems with termites, mold, or rotting and the concrete/metal stud system is non-combustible. The system also has high sound insulation values for better building acoustics, which is important for apartment units (see Appendix A). Compared to timber structures, the Infinity system will produce a lower life cycle costs as maintenance of the system will be lesser. POTENTIAL SOLUTION To improve the schedule and life cycle costs, the effectiveness of an Infinity system will be analyzed in the Apartment Building. A redesign of the apartment unit structural system will be performed with the Infinity system and will be analyzed from a construction cost, schedule, and life cycle standpoint. The constructability of the Infinity system will be analyzed, as well. 12/15/2014 Analysis 2 Page 5

9 METHODOLOGY Investigate specific layout and design of current timber structural system Design a typical bay of Infinity System Perform structural analysis of new system Analyze constructability of Infinity system Estimate differences in cost and schedule from original timber structure Compare life-cycle costs of timber and Infinity system RESOURCES Ray Sowers (experience with Infinity System) John O Keefe, Clark Residential Infinity Structural System consultants PSU Structural Faculty o Dr. Thomas Boothby o Dr. Linda Hanagan PSU Structural Classmates o Adam Jesberger Principles & Practices of Commercial Construction by Woods, Andres, and Smith RS Means EXPECTED OUTCOME Using the Infinity system, the initial cost may be more but future costs, such as maintenance, should be reduced when compared to the timber structure. Because the Infinity system consists of prefabricated metal stud walls, there will be less congestion on site, improved quality, and faster installation. This will increase production rates and produce schedule savings. Because of the necessary partial redesign of the structure, this depth will provide an opportunity for a structural breadth (see Appendix A). Additionally, because of the increased sound insulation of the Infinity system, this depth will also provide useful information towards an acoustical breadth. 12/15/2014 Analysis 2 Page 6

10 ANALYSIS 3: CRITICAL INDUSTRY ISSUE - 3D MODELING PROBLEM IDENTIFICATION The Apartment Building did not utilize any BIM use during design or construction of the project. Because of this, there were many issues in the construction phase due to poor planning. Additionally, many projects are similar and can benefit from the use of 3D and 4D models to visualize construction activities, sequences, and avoid rework. Based on the growing interest for BIM and technology, as identified at the PACE roundtable, a research of 3D models in conjunction with visualizing construction will be performed to understand the benefits and how they can be applied to the Apartment Building. BACKGROUND RESEARCH BIM is a popular process in the construction currently, with applications to improve quality, save money and time in schedule during the design, construction, and maintenance phases. An effective way to communicate construction planning and sequences is through 3D visualizations, such as with the software VITASCOPE, which stands for VIsualizaTion of Simulated Construction OPErations. VITASCOPE is a program used for the visualization of simulated construction processes and developing higher-level construction visualization tools (Vineet). The program can visualize many different types of construction and is an open source software. CAD models can be used with VITASCOPE to recreate a virtual world of the process. The advantages of using a 3D modeling software such as VITASCOPE are avoiding rework by planning the work in a virtual setting before construction and improving the quality, constructability, and scheduling of processes by being able to control and understand fully before construction commences. METHODOLOGY Obtain CAD files from DAVIS to use for 3D modeling Speak with Jon Colosimo, DAVIS PM, about BIM use on his project Interview Dr. Vineet Kamat and/or Dr. John Messner to learn more about visualization of construction models Develop tools to create a 3D visualization of the Apartment Building s sequencing and site logistics 12/15/2014 Analysis 3 Page 7

11 RESOURCES General-Purpose 3D Animation with VITASCOPE by Dr. Vineet Kamat Dr. John Messner (PSU BIM Expert) Dr. Vineet Kamat o Civil Engineering Faculty at University of Michigan and Creator of VITASCOPE VITASCOPE website, Jon Colosimo o Project Manager on similar DAVIS project that utilized BIM GOAL OF RESEARCH The goal of this research is to understand the benefits of 3D visualizations of construction processes. At the conclusion of this research, a better understanding of the VITASCOPE software should be had with an application to the Apartment Building. The goal is to create a visualization of a specific construction process of the Apartment Building and present to DAVIS and the owner to show the benefits of BIM during design and construction. 12/15/2014 Analysis 3 Page 8

12 ANALYSIS 4: SITE LOGISTICS ALTERATIONS OPPORTUNITY IDENTIFICATION The Apartment Building sits on a somewhat congested site, with material laydown in a small corner to the southeast and a temporary precast yard in the northwest corner. To increase the production rates and accelerate the schedule there is an opportunity to use a tower crane to place the 22 cast-in-place podium structure. This will modify the site logistics and will require a design of a crane foundation. Using a tower crane will explore different sequences and constructability of the CIP podium while providing the opportunity to use 3D modeling as research in Analysis 3. As the owner places schedule as their highest priority, in order to rent the units as fast as possible, utilizing a tower crane will be beneficial for the owner and contractor. BACKGROUND RESEARCH On this project, the CIP subcontractor opted to not use a tower crane to decrease their costs, even though the utilization of a tower crane was suggested by the contractor. A similar project by the contractor uses two tower cranes, mostly used because of a large 3 level underground parking garage, so the benefit of a tower crane has been realized by the contractor. The sequencing of the CIP podium starts with building 100, with building 200 proceeding about 2 months later. The reason for this delay is due to building 200 s footprint being utilized as the precast yard for the parking garage. Many projects of this size have been known to use one or more tower cranes to improve efficiency and productivity in sequencing and also reduce the equipment numbers on site (such as multiple mobile cranes and/or boom trucks). Additionally, tower cranes are powered by electricity which is a cleaner and more sustainable source, opposed to fuel. POTENTIAL SOLUTION The use of a tower crane will be analyzed, which will bring changes to cost, schedule, site coordination, and constructability. The analysis will focus on the benefits of the tower crane use on the CIP podium structure versus the current use of hydraulic cranes. Site logistics will have to be modified to incorporate the tower crane on site, as well as designing a foundation to support the crane. The precast yard in the footprint of building 200 will be moved so the start of that structure is not delayed. To maximize efficiency of sequencing the two buildings, a 3D visualization will be created with VITASCOPE to show the use of the tower crane. The 12/15/2014 Analysis 4 Page 9

13 analysis will result in a comparison of costs, schedule acceleration, site utilization, and sequencing. METHODOLOGY Inquire on details about CIP subcontractor current use of equipment and logistics o Collect durations and productivity for current methods Determine loads for crane selection Design crane foundation Incorporate tower crane into site logistics plans o crane radius and location within site Calculate additional costs and possible savings of using tower crane Calculate productivity when tower crane is used and evaluate the schedule savings o including crane erection and teardown Create a 3D visualization with VITASCOPE to show how using the tower crane will be beneficial for turnover to owner RESOURCES AccuCrete, cast-in-place subcontractor The Apartment Building project team PSU Structural Faculty Dr. John Messner VITASCOPE website, Principles & Practices of Commercial Construction by Woods, Andres, and Smith AE 476 notes on temporary power for tower cranes RS Means EXPECTED OUTCOME At the conclusion of this analysis, a recommendation to use or not use a tower crane will be given based on the schedule savings, cost, and sequencing. It is expected that there will be a higher upfront cost due to the cost of the crane and additional temporary power requirements, but the cost benefits of finishing the schedule sooner and obtaining tenants for the apartments may outweigh these initial costs. Additionally, if the tower crane can increase the schedule to be dried in before the winter months, there may be an opportunity to save on temporary heat. 12/15/2014 Analysis 4 Page 10

14 The tower crane should be able to accelerate the schedule by increasing productivity and work flow of the CIP podium of building 100 and 200. A 3D model will also be available to the contractor to show how BIM can be used to plan work before it begins. 12/15/2014 Analysis 4 Page 11

15 CONCLUSIONS At the conclusion of these analyses, it will be written that the Apartment Building will have improved constructability sequencing, better life cycle costs, and an improved schedule to finish the project earlier. Most of these analyses focus on accelerating the schedule, which the owner will desire so that they will be able to rent out the apartment units as soon as possible. Using linear scheduling coupled with simultaneous work on the finishes of building 100 and 200, the project will be able to accelerate and/or catch up on work that has fallen behind, as well as creating a simple, graphical representation of the schedule that can easily be read in the field. Modifying the residential structure to an Infinity system will increase the life cycle costs of the building as well as improve the constructability of the structure with the advantage of prefabricated metal stud walls. A research will be performed on BIM and how 3D visualizations of construction processes can benefit the contractor and will applied to an analysis of the effects of using a tower crane for the CIP structure, which will improve productivity and quality of construction. OVERALL WEIGHTING BREAKDOWN Table 1 suggests a weighting of my Spring 2015 grade based on the 4 analyses and embedded breadths. Table 1: Overall Breakdown Analysis % of Grade Analysis 1: Linear Scheduling of Interior Trades 20% Analysis 2: Timber Structure Modification 35% Analysis 3: Critical Industry Issue - 3D Modeling 15% Analysis 4: Site Logistics Alterations 30% 12/15/2014 Conclusions Page 12

16 APPENDIX A

17 BREADTH STUDIES STRUCTURAL BREADTH An opportunity to perform a structural breadth is present in analysis 2 and 4. By modifying the timber structure to the Infinity system in analysis 2, a typical bay will need to be designed and analyzed to understand the impact on lateral systems. This analysis will create a better understanding of the structural properties of wood and the Infinity system, all while learning of the constructability aspects of these systems. Additionally, analysis 4 will present a structural breadth opportunity. In order to add a tower crane to the site, a foundation pad to the weight of the crane and crane loads will have to be designed and constructed. An investigation will be performed to obtain the size the foundation necessary, the excavation required, reinforcement needed, and to find the best placement on the site. ACOUSTICAL BREADTH An opportunity to perform an acoustical breadth will present itself in analysis 1 and 2. Because noise isolation is important in living spaces that have shared walls, it will be a good selling point to the tenants seeking to live in the Apartment Building for a great quality of sound isolation of each unit. By having an in-depth look at the interior finishes in analysis 1, there will be an opportunity to alter some of these finishes to create a higher sound transmission class of wall and floor assemblies of the apartment units. Additionally, analysis 2 will be changing the structure to a metal stud system, which increases the STC of the wall assembly. An analysis will be conducted of the current system and compared to a redesigned system that will offer superior sound isolation from unit to unit. Overall, the criteria evaluated will be STC of wall and floor assemblies and noise criterion of the room. A modeling of a typical unit may also be performed using the software, Dynasonics AIM, to calculate mechanical background noises. Resources used will be the notes of AE 309 and AE 458, as well as Penn State s building acoustics professor, Dr. Michelle Vigeant. 12/15/2014 Breadth Studies Page 14

18 APPENDIX B

19 SPRING ANALYSIS SCHEDULE The following page shows the timeline for work to be done of the 4 proposed analyses and breadth studies. 12/15/2014 Spring Analysis Schedule Page 16

20 Spring 2015 Semester Projected Timeline January May 2015 The Apartment Building Rockville, MD Brian Bernens - Construction Option Advisor: Rob Leicht Milestone #1 January 23 Jan-12 Jan-19 Jan-26 Feb-2 Identify what crews to focus on and obtain current production Calculate production of simultaneous crews in both bldgs. Feb-9 Milestone #2 February 13 Feb-16 Feb-23 Mar-2 Milestone #3 March 6 Mar-9 Mar-16 Mar-23 Mar-30 Milestone #4 April 3 Apr-8 Apr-13 Apr-20 Apr-27 May-1 Create Linear Schedule Research current system production and cost Research Infinity System Design Infinity system and perform structural analysis (Breadth) Perform Acoustical Analysis (Breadth) Calculate schedule savings and cost impacts Calculate cost impacts Calculate schedule savings and cost impacts Research VITASCOPE and related programs Research site logistics options and soil conditions Obtain current usage and production of CIP subcontractor Interview personnel to find out uses of 3D visualizations Determine crane loads Obtain CAD files Summarize results and provide recommendations S P R I N G B R E A K Compare structural systems and summarize results F I N A L R E P O R T P R E S E N T A T I O N S S E N I O R B A N Q U E T Design crane pad Calculate productivity, schedule savings, and cost impacts Create VITASCOPE simulation VITASCOPE Compare methods and summarize Revise Proposal Develop Presentation Slides Finalize Report and Run Through Presentation Legend Analysis 1: Linear Scheduling of Interior Trades Analysis 2: Timber Structure Modification Analysis 3: Critical Industry Issue - 3D Modeling Analysis 4: Site Logistics Alterations General Course Tasks Milestone Milestone Activity Update Analysis 1, 2, and 4 research 100%; Analysis 3 research 75% Analysis 1 production calculated 100%; Analysis 2 design (structural breadth) 75%; Analysis 3 interviews 100%; Analysis 4 crane foundation research and design 100% Acoustical breadth 100%; Analysis 1 cost and schedule 75%; Analysis 2 cost and schedule 100%; Analysis 3 100%; Analysis 4 productivity, schedule, and cost impact 100%; VITASCOPE model 75% 100% all analyses; Report finished