Categories
Uncategorized

Quantitative Assessment of Building Constructability

Building Constructability

Despite the fact that applying constructability concepts in building designs have led to savings estimated within a range of 1% to 14% of the capital cost, the construction industry still lacks an advanced tool to assess and check for constructability Building Constructability implementations in designs. Therefore, the objective of this research is to propose a quantitative assessment of building constructability, which transforms the subjective assessment of constructability knowledge to a quantified value so that it is easy to analyze and improve building design. The proposed methodology uses the advancement of object oriented Building Information Model (BIM) and 4D simulation model to serve as a data repository models for the constructability assessment platform. Factors affecting constructability of building designs have been identified and relatively weighted using Analytical Hierarchy Process (AHP) technique based on a questionnaire survey collected throughout the Canadian provinces. Evaluation criteria are also developed to assist the designer to evaluate the design proposals. The outcome shows that the proposed method provides the designer an accurate and faster mode in evaluating project constructability by using the parametric features from BIM and taking the advantage of spatial relationship between building components.

Construction is a dynamic, complex, as well as fragmented process, and the traditional system of construction separates the two main disciplines of design and construction, where designers and contractors rarely communicate before the initiation of the construction phase. Early in 1982, The Business Roundtable defined a “constructability program” where a potential return on investment of 10:1 was reported by applying constructability [1] . National Institute of Standards and Technology (NIST) conducted a study in 2004 and reported that the lack of Architecture/Engineering/Construction (AEC) interoperable software was costing the industry $15.8 Billion annually [2] .

With the continuous advancement in technologies, new techniques are constantly being developed in order to improve engineering implementations for the construction industry. One of these promising developments is Building Information Modeling (BIM) where it facilitates a more integrated design and construction process that results in better quality buildings at lower cost and reduced project duration [6] . The American Society of Civil Engineer (ASCE) reports that BIM technology can be used to validate a new constructible tool [7] . BIM provides the construction community a complete 3D database that can be used for estimating, scheduling, detailing, advance bill production, automated shop drawing, and construction planning for all of the trades. In addition, by adding time information to the BIM model, 4D models facilitate the testing of different design and execution sequencing alternatives so as to achieve better constructability. Therefore, by integrating BIM and 4D simulation, quantitatively assessing the constructability of a building design becomes a novel, feasible and necessary method. The present paper describes the proposed new method and relative implementation and development.

The benefits of improved constructability have been associated with the time, cost, quality, and safety performance of a project, together with other intangible benefits. Quantifying assessment of designs, constructability review, and implementation of constructability programmers are the three most commonly employed approaches. Quantifying assessment of designs enables an objective evaluation of constructability attributes since results are comparable. Using this approach, two issues were addressed. On one hand, it is reasonably practicable and manageable for assessments to be made because it is done using the finished design product rather than evaluating the design process. On the other hand, it is difficult to comprehensively take into account all relevant factors affecting constructability into the assessment system [5] .

Singapore has pioneered in the field of quantifying constructability based on a scheme known as the Buildable Design Appraisal System (BDAS). The concept is based on a “3S” design principle in which a design is tested for constructability issues with respect to Standardization, Simplicity and Single Integrated Elements. A similar approach was used for assessing constructability proposed for the Hong Kong construction industry in 2007 [5] . A constructability multi-attribute system (BMAS) was developed for assessing constructability of designs in Malaysia [8] . The assessment was based on 6 principles with identified factors for each principle which were developed through a literature review, questionnaire survey and brainstorming sessions. Another assessment method based on cognitive models (CM) was proposed for constructability assessment for steel frame structures [9] . It was based on the use of interviewing techniques to understand problem solving and the development of knowledge models for automated constructability assessment. [10] developed a fuzzy Quality Function Deployment (QFD) system to support constructible design decision making. It provided a systematic and structured method to support the integrated decision-making process of constructible designs, and applied a fuzzy set theory to facilitate the processing of design-relevant QFD information.

It was found that previous assessment platforms were in complex calculations, dependent on governmental benchmarks, and lack of time factor. Detailed comparison can be found in [11] . In addition, working schedule was not considered in any of the previous work introduced above. The analysis of the time module throughout all construction phases was essential for any constructability evaluation, as indicated by [12] . Therefore, there is a need for an integrated assessment platform to provide the user a project specified model, with clearly defined rules, understandable criteria, and flexible interactive system.

As discussed in the Introduction, BIM is playing a crucial role in research and development fields of construction information integration and interoperability. BIM is defined as the creation and use of coordinated, consistent, computable information about a building project. These various forms of information had a parametric nature where they can be used for design decision making, production of high-quality construction documents, prediction of building performance, cost estimating, and construction planning [13] . By having the possibility to build the whole project virtually before physical construction begins, BIM adds a level of accuracy to both quantities and quality issues that overcomes the shortenings found when traditional processes of design and documentation are used. Traditional 2D and 3D CAD programs don’t represent a space because it doesn’t exist as a distinct physical entity. However, a space entity is a fundamental part of a BIM model, and includes the proper relationships to its corresponding walls, ceilings, floors, etc. Thus, spatial information needed for constructability analysis can be easily obtained from an application using a BIM data model, whereas several complex calculations had to be required to derive the same information from an application using a traditional geometric data model [14] .

As stated earlier, certain constructability factors are of a qualitative nature which makes it exceptionally difficult to quantify their impact on design. For example, many studies have been done on analyzing material access throughout the construction site, and all the contributions included only ideas and knowledge bases to improve proper material accessibility ( [15] [16] ). There is a little evidence in literature that reported a formal procedure or standard process for material access analysis. In order to analyze qualitative constructability factors, the present research argues that visual analysis can be used as basis for studying such qualitative factors if they were properly associated with constructability knowledge.

In addition, time information can be integrated into the BIM model, which utilizes a three-dimensional project geometry into an environment where the effect of time schedule over construction can be visualized. A virtual object-oriented 4D model had the potential to support automated constructability assessment and to assist a project team in identifying constructability issues early in the design and construction phases [17] . This improved the identification of possible mistakes or conflicts done unknowingly at an early stage of a construction project, and thus enabled project stakeholders to optimize the construction schedule as much as possible [18] .

The authors of the present paper have been exploring the integration of quantitative constructability assessment with BIM and 4D models for a long time. Based on our previous research results ( [19] [20] ), a complete methodology and implementation are described in the present paper.

Categories
Uncategorized

Dry Weather Sanitary Sewer Overflows

Dry Weather Sanitary

This study investigates arrivals of sanitary sewer overflows collected from a Dry Weather Sanitary municipality. The data set consists of recorded overflows from 2011 to 2014 during Dry Weather Sanitary . Reliability analysis is conducted upon each data set. The Weibull distribution is adopted to evaluate the data sets. The results show that the arrival of dry weather SSOs cannot be simply modeled with a Poisson process that is featured with a constant arrival rate. For annual data set, 2-parameter Weibull generally has an acceptable fitting (except 2014 data). The shape parameters are close to 1 or a little greater than 1, indicating relatively constant arrival rate or slightly increased rate. For the entire data set, the 3-parameter Weibull distribution is able to fit the data well. The shape parameter is also greater than 1. Therefore, an increased SSO arrival rate is noticed for this data set. There are needs to make more efforts in maintaining the sewer system.

The sanitary sewer overflow (SSO) is a condition in which untreated sewage is discharged from a sanitary sewer into the surroundings before reaching to the treatment facility. The cause of SSOs can be of multiple sources, such as blockage of sewer pipelines, infiltration of storm water into the line during rainfall, pump station failures, and broken or collapsed pipe lines. Therefore, in the sewer pipeline management, the sanitary sewer overflow (SSO) is an important indicator of the system’s performance. Such SSOs are common issues to all municipalities. It is meaningful to study such events to assist decision makers in the facility management.

The arrivals of those events may be assumed to random. Such assumption of independent successive events leads to the Poisson process. In a Poisson process, the inter-arrival times display an exponential distribution [1] . Such memory-less property provides advantages in modeling events in sequence. In civil engineering, this approach has been applied in modeling rainfalls [2] , and accident frequency analysis [3] .

In real life, the homogenous memory-less assumption may not be justified. The prediction may also be conservative [4] . The process can be more accurately modeled with a non-homogenous model. Existing reliability models include Crow’s model [5] and Cox-lewis’ mode [6] , both use the Weibull distribution to fit the “time to failure” data. In this study, in order to explore the arrival of overflows during the dry weather, the Weibull distribution is used to verify the pattern of SSO arrivals. The results will assist stakeholder and decision makers in the management of sewer facilities [7] .

In the sewer system management, research has been conducted in several directions. In general, it can be categorized into three major concentrations. The first concentration is the reliability analysis of the system. This method focuses on the failure data and explores the reliability through the data analysis. Atypical example is the research conducted by Jin and Mukherjee [7] [8] . In this research, the authors focused on the blockages, by using a set of data collected on a sewer system. They proposed methods to explore the arrival patterns deeply. They also proposed a life time trend based on the reliability analysis. Applications are also explored with specific examples demonstrated. Similar research has also been conducted in terms of hydraulic evaluation of systems [9] – [12] ; and situational simulation to support decision making in co-dependent infrastructure systems [13] .

The second category is the condition prediction. The Markov chains model has been applied extensively in this research concentration. For example, Wirahadikusumah et al. discussed several challenging issues in the sewer pipe condition prediction [13] . They presented the Markov chains model, which is the most popular technique in simulating the condition deterioration. However, the condition transition probability estimation is a huge challenge. Jin and Mukherjee further proposed specific methods to estimate the probabilities [14] [15] . They further investigated the sensitivity of Markov chains model, which is a big step in this research category. Other related studies can be found in [16] – [19] .

The third category can be the life cycle analysis of the sewer system. Both life cycle cost and life cycle assessment have been conducted upon the system. For example, Najafi and Kim compared the life cycle cost of the trenchless and conventional open-cut pipeline [20] . They conclude that the trenchless method has its advantages. Lassaux et al. conducted a life cycle assessment of the water from the pump station to the wastewater treatment plant [21] . Detailed inventories are summarized in the study. Jin conducted both the life cycle cost and life cycle assessment of three rigid sewer pipes, namely, non-reinforced concrete pipe (NRCP), reinforced concrete pipe (RCP) and Vitrified clay pipe (VCP) [22] . Detailed costs and environmental impacts are presented in the study. Other related research can be found in [23] – [25] .

This research is similar to the study conducted by Jin and Mukherjee [7] . Instead of focusing on the sewer blockage, this study evaluates the SSO issues under the dry weather condition. In order to investigate the reliability of the sewer system via SSO data, the Weibull distribution is applied upon various sets of SSO data combinations.

Categories
Uncategorized

Standardization of BIM Objects

BIM Objects

The management of information systems contributes to the economic development of the construction sector by organizing and structuring technical and BIM Objects economic information. It is proposed how BIM Objects (Building Information Modelling) and a Portuguese information system-ProNIC (abbreviation for Protocol for the Standardization of Construction Technical Information) may be interconnected. The scope of this information transmission in construction sector is a step to solve several problems that have been identified in conception of BIM models.

In Portugal, the use of BIM (Building Information Modelling) methodology in the construction industry is not yet widespread [1] . However, it is unquestionable that BIM models are a reality to consider with extremely important contributions, not only for the design phase, but also for the remaining ones, contributing to the development of construction sector [2] [3] . Its implementation in the medium and long term will bring success and effectiveness to the sector, considering that it is a methodology for information and communication sharing between all stakeholders and at all phases of a building life cycle [4] .

The integration of BIM models with other tools to support the construction process is important to spread their use. The existence of technical and economic structured and standardized information related to each building element is essential for supporting the designers of all engineering projects. Similarly, the use of information management systems maintains this information throughout all stages of building life cycle, improving the quality and accessibility of information and contributing to the economic development of the construction sector [5] [6] . ProNIC (Portuguese abbreviation―Protocol for Standardization of Technical Building Information) [7] provides an important contribution with technical and economic structured and standardized information. In addition, ProNIC is already developed to work in a collaborative environment for all stakeholders.

The present communication aims to show how information management systems contribute to support the construction industry. It describes and proposes how technical and economic information about construction, existing in ProNIC, can be transferred to standard BIM objects, supporting the engineering projects and addressing the various issues that have been identified within transmission of information from the design phase to the subsequent stages of the building life cycle.

The Construction Information Classification Systems (CICS) have been growing and nowadays have a major role on the organization of the information that is produced by the construction sector. Since their beginning the CICS were developed to solve specific problems on the construction sector. The development of the construction brought higher complexity to design process and a bigger amount of technical information to the process. The CICS followed this development contributing to a better organization and efficiency [8] .

Actually, there are some modern CICS developed internationally, that are a reference for the construction sector. Next is presented some of them, their philosophy and applicability.

Uniclass (Unified Classification for the Construction Industry) is a new classification scheme for the construction industry. It is intended for organizing library materials and for structuring product literature and project information. It incorporates both CAWS (Common Arrangement of Work Sections for building works) and EPIC (Electronic Product Information Co-operation), a new system for structuring product data and product literature. Uniclass comprises 15 tables, each of which represents a different broad facet of construction information. Each table can be used as a “stand alone” table for the classification of a particular type of information, but, in addition, terms from different tables can be combined to classify complex subjects [9] [10] .

The OmniClass Construction Classification System [11] is a means of organizing and retrieving information specifically designed for the construction industry. OmniClass is useful for many applications in the area of Building Information Modeling (BIM), from organizing reports and object libraries to providing a way to roll up or drill down through data to get the information that meets your needs. OmniClass draws from other extant systems in use to form the basis of its tables wherever possible (MasterFormat for work results, UniFormat for elements, and EPIC (Electronic Product Information Cooperation) for products). OmniClass consists of 15 hierarchical tables, each of which represents a different facet of construction information. Each table can be used independently to classify a particular type of information, or entries on it can be combined with entries on other tables to classify more complex subjects.

The Industry Foundation Classes (IFC) [12] data model is intended to describe building and construction industry data. It is a platform neutral, open file format specification that is not controlled by a single vendor or group of vendors. It is an object-based file format with a data model developed by buildingSMART (formerly the International Alliance for Interoperability, IAI) to facilitate interoperability in the architecture, engineering and construction (AEC) industry, and is a commonly used collaboration format in Building information modeling (BIM) based projects. The IFC model specification is open and available. It is registered by ISO and is an official International Standard ISO 16739:2013 [13] .

Categories
Uncategorized

Implementing Building Information Modelling

Building Information Modelling

Building Information Modelling (BIM) is a process involving generation and management of digital representations of physical and functional characteristics of places, which can be exchanged or networked to support decision-making in architecture, engineering and construction (AEC) sector. Building Information Modelling is a relatively new technology in an industry typically slow to adopt changes, especially in Portugal. The present paper aims to frame the international implementation of BIM in order to propose a roadmap to spread the use of BIM methodologies in Portugal in the next decade.

BIM is a technology, and not a specific program, that offers an integrated platform to improve design, increase the speed of delivery for design and construction, and provide a flow of information without breaks.

The use of BIM goes beyond the planning and design phase of the project, being extended throughout the building life cycle, of several infrastructures (water, wastewater, electricity, gas, waste, roads, bridges, ports, houses, apartments, schools, hospitals, shops, offices, factories, warehouses, prisons, etc.).

BIM has been on the rise for the past decade. The AEC (Architect, Engineering and Construction) industry is adapting to increased demands for the use of BIM during the design and construction phase of construction projects. Building owners, private and public are increasingly requiring that BIM is used on their projects as the method has proven to have a positive impact on the construction process in many aspects e.g. clash detection, better visualization, energy analyze or its effect on buildings LCC (Life Cycle Cost); other parts of the method have been proven to save time and cost as well as delivering better product to the building owner [1] .

The BIM method is on different maturity levels in different countries. Different countries have their own BIM standards and different organizations that contribute to writing and updating the standards. The different types of standards are necessary since each region has their own regulations and traditions within the construction industry so the standards need to be adapted to different cultures Are also overviewed what organizations are leading the implementation of BIM in most relevant countries.

Categories
Uncategorized

Mud Brick in Building Construction

Building Construction

The use of earth construction is well established in energy Building Construction efficient housing. Mud bricks consist of clay, water, and binding material such as rice husks or Building Construction straw. The advantages of mud brick include its low-cost and great thermal behavior. Although mud brick is considered one of the oldest construction materials, engineers and builders do not have enough information about its mechanical properties. Also there is no accurate design code to follow before construction. This study is devoted to enhance the low compressive strength of mud brick without sacrificing its low thermal conductivity properties. The experimental program in this research includes the use of different admixtures to increase the compressive strength of the basic mud mix. The experimental results show that the increase of cement ratio, as ingredient to a certain limits, can lead to an optimum compressive strength of the brick.

Earth as mud bricks, has been used in building construction for thousands of years and approximately 30% of the world’s present population still live in earthen shelters [1] . Mud brick is an inexpensive, environmentally- friendly and abundantly-available building material. It has been used extensively for building construction around the world, particularly in extreme hot, dry desert climates like that of most Arabian countries [2] . In these countries, mud bricks are made by blending mud and water together into a goopy mixture. Traditionally straw is added to improve tensile strength, and may prevent mud bricks from cracking. The mud brick is then shaped in a mold of almost any size or shape, or by hand. The brick mixtures are then laid to dry in the heat of the sun for about 25 days before use [3] – [6] . Figure 1 shows new unlaid mud bricks in the Jordan River, while Figure 2 shows buildings made from mud bricks in an old town in Niger.

Mud bricks have several advantages over other conventional building materials, e.g., concrete masonry. These advantages include: a very minimal manufacturing process; skilled labor is not necessary; mud is available from natural resources; inexpensive construction materials; and mud structures are able to perform satisfactorily under hot environmental conditions [7] . However, there are many disadvantages in using mud bricks as building materials. These include: mud brick may tend to erode under rain impact; absorption of water causes swelling of mud brick, while evaporation of water from the mud brick gives rise to shrinkage and cracking; and mud brick is a relatively fragile material, which cannot resist earthquake hazards.

It is known that mud brick technology has been widely used in desert countries due to the widespread existence of silt and clay deposits in these areas. The importance of using mud brick as a building material, however, has not been seriously investigated through scientific experimentation. Therefore, this study aims to investigate: improvements in mud brick consolidation by increasing its durability; and imparting water penetration to mud brick. In this research, the effect of different mud brick components on strength and thermal conductivity properties are investigated. The basic mixture consists of mud (clay and sand), straw and water. Many additives are provided to the basic mixture in order to improve brick properties.

The overall aim of this study is to determine, through extensive experimental investigation, the effect of different mud brick ingredients on strength and absorption, and utilize these results in a forthcoming study on thermal-conductivity properties. With this in mind, the specific objectives of the study are to improve mud brick consolidation by using materials such as soluble silicate, ethoyl silicate, silanes or siloxanes, isocyanates and various polymers agents to treat mud brick permeability. In addition, the effect of using metallic fibers to improve mud brick durability is investigated.

Categories
ARTIKEL

Model Ideal Siklus Bahan Bakar Sepeda Motor

Model Ideal Siklus Bahan Bakar Sepeda Motor

Model siklus bahan bakar sepeda motor yang ideal yang Anda pilih sendiri haruslah model yang memberikan semua manfaat yang Anda butuhkan tanpa menghabiskan terlalu banyak sumber daya Anda. Anda harus melihatnya dengan sangat serius sebelum memutuskan model tertentu. Anda juga harus mempertimbangkan berbagai faktor seperti harga siklus bahan bakar, kinerjanya, dan daya tahannya. Anda harus tahu fakta bahwa di pasar saat ini ada begitu banyak siklus bahan bakar yang tersedia untuk pelanggan di luar sana sehingga Anda tidak perlu puas dengan model siklus bahan bakar yang lebih rendah hanya karena harganya murah. Jika Anda memilih model yang lebih murah, itu mungkin tidak cukup tahan lama, mungkin tidak berkinerja baik, atau mungkin hanya menghabiskan terlalu banyak sumber daya Anda untuk dijalankan.Saat memilih model siklus bahan bakar sepeda motor yang ideal, Anda juga harus memastikan bahwa Anda membeli yang tepat untuk Anda. Misalnya, jika Anda ingin menggunakan sepeda ini untuk keperluan komuter, maka Anda harus memilih sepeda motor yang ukurannya tidak terlalu besar tetapi cukup berat untuk dibawa ke mana pun Anda pergi. Jika Anda menginginkan sepeda untuk tujuan kompetisi dan tes, maka Anda harus memastikan bahwa sepeda Anda memiliki semua fasilitas yang akan membantu Anda memenangkan perlombaan. Contoh yang baik dari hal ini adalah memiliki kursi dan setang yang nyaman. Selain itu, jika Anda ingin balapan di jalan tanah atau jalan yang mulus, maka Anda harus membeli sepeda motor trail daripada yang mulus.Anda juga perlu memeriksa mesin dari siklus bahan bakar untuk memastikan bahwa itu telah dirancang sedemikian rupa sehingga Anda tidak memerlukan banyak perawatan di masa depan. Faktanya, selalu lebih baik menggunakan sepeda dengan mesin yang lebih kecil dibandingkan dengan yang lebih besar. Mesin yang lebih kecil akan memberi Anda tenaga yang lebih baik tanpa menghabiskan terlalu banyak sumber daya Anda. Selain itu, saat mesin hidup, tekanan di udara dan suhu di dalam mesin akan diamati. Dengan demikian, ini akan membantu Anda memutuskan model yang ideal untuk kebutuhan Anda.

Itu selalu terbaik untuk membeli sepeda motor dari dealer terkemuka. Ini akan membantu Anda mendapatkan model yang tepat pilihan Anda dengan harga terbaik. Selain itu, sebelum membeli sepeda, Anda harus meluangkan waktu dan mempelajari berbagai fitur yang ditawarkan masing-masing model sepeda motor. Sangat penting untuk menentukan apa yang sebenarnya Anda butuhkan untuk jenis perjalanan yang ingin Anda lakukan sehingga Anda dapat menghindari kesalahan dalam memilih model sepeda motor ideal Anda.

Terakhir, sebelum Anda membeli model siklus bahan bakar sepeda motor yang ideal untuk kebutuhan Anda, Anda harus memastikan bahwa Anda telah memeriksa kredensial penjual secara menyeluruh. Bahkan, Anda dapat mengunjungi Better Business Bureau untuk melihat apakah ada keluhan yang diajukan terhadap dealer. Di sisi lain, Anda dapat mengunjungi Departemen Perhubungan untuk melihat apakah penjual memenuhi standar keselamatan federal. Selain itu, Anda juga harus mempertimbangkan undang-undang setempat di daerah tersebut sehingga Anda dapat memilih siklus bahan bakar yang tidak akan sulit untuk dirawat.

Ada banyak faktor yang perlu Anda pertimbangkan saat membeli model yang ideal untuk Anda. Namun, Anda harus ingat bahwa lebih baik menghabiskan sedikit lebih banyak uang di muka dibandingkan dengan apa yang akan Anda keluarkan nanti untuk pemeliharaan. Tentu saja, dalam jangka panjang, disarankan untuk membeli model sepeda motor yang ideal karena akan memberi Anda nilai terbaik untuk uang yang akan Anda keluarkan untuk itu. Namun, jika Anda ingin menghemat uang dan memiliki sepeda motor murah, maka disarankan untuk mempertimbangkan untuk membeli model bekas. Anda selalu dapat menemukan sepeda motor bekas yang bagus di dealer atau pelelangan

Categories
Uncategorized

Peningkatkan infrastruktur bendungan dan jembatan

Untuk kedua kalinya secara berturut-turut, Peningkatkan infrastruktur bendungan dan jembatan Amerika mendapatkan nilai D + dari American Society of Civil Engineers. ASCE menerbitkan kartu laporan Peningkatkan infrastruktur bendungan dan jembatan ini setiap empat tahun, menilai jembatan, bendungan, taman, bandara, rel kereta api, dan hubungan penting lainnya di AS. Fakta bahwa nilai Peningkatkan infrastruktur bendungan dan jembatan keseluruhan bangsa kita tidak meningkat sejak rapor terakhir pada tahun 2013 menunjukkan bahwa investasi besar sudah lama tertunda.

Presiden Trump telah berjanji untuk mengusulkan investasi senilai US $ 1 triliun selama 10 tahun untuk memodernisasi infrastruktur negara. Jika pemerintahan Trump menemukan cara untuk mendanai rencana semacam itu, ia akan menghadapi banyak pertanyaan mendesak tentang bagaimana menggunakan uang tersebut.

Strategi yang paling mungkin dan logis akan mengejar kombinasi proyek konstruksi baru, perbaikan dan retrofit, yang dipilih untuk memberikan hasil maksimal. Memperbaiki struktur biasanya lebih murah daripada retrofit dengan menambahkan komponen baru, yang pada akhirnya lebih murah daripada membangun struktur baru.

Di Colorado State University (CSU) kami sedang mengembangkan dua strategi yang dapat memperpanjang umur struktur seperti jembatan dan kunci navigasi. Pertama, kami mengidentifikasi interval yang sesuai antara inspeksi, untuk meminimalkan biaya inspeksi tanpa mengurangi keselamatan publik. Kedua, kami menggunakan metode inovatif untuk meningkatkan masa pakai struktur secara efektif, mengurangi kebutuhan akan proyek konstruksi baru yang mahal.

Retak di jembatan yang sudah tua

Amerika Serikat memiliki 614.837 jembatan, yang hampir 40 persennya berusia 50 tahun atau lebih. Karena banyak yang awalnya dirancang dengan masa pakai 50 tahun, tidak mengherankan jika mereka merendahkan. Menurut ASCE, rata-rata ada 188 juta perjalanan melintasi jembatan yang secara struktural tidak memadai setiap hari pada tahun 2016.

Di jembatan baja, kerusakan struktural lokal menghasilkan kondisi lemah yang oleh para ilmuwan material disebut sebagai kelelahan. Pembebanan siklis dari tahun-tahun berlalu lintas kemudian menyebabkan terjadinya retakan. Sebagian besar jembatan baja yang lebih tua mengalami kelelahan dan akhirnya retak karena kode yang ada pada saat dirancang tidak cukup mengatasi masalah ini, atau karena jembatan tersebut membawa beban lebih berat daripada yang semula dirancang untuk ditanggung.

Pertumbuhan retak fatik umumnya dapat dikelola melalui perbaikan rutin tanpa mengorbankan kinerja jembatan. Namun, jika retakan tidak diperbaiki, retakan tersebut dapat tumbuh dengan cepat, yang dapat menyebabkan kegagalan besar. Ini berarti sangat penting untuk mengukur laju pertumbuhan retakan, dan untuk memahami bagaimana pertumbuhan retakan yang cepat dapat mempengaruhi integritas jembatan.

Meningkatkan infrastruktur bendungan dan jembatan

Jembatan mana yang harus diperbaiki dulu?

Beberapa jembatan merupakan prioritas tinggi untuk pemeriksaan dan perbaikan karena American Association of State Highway and Transportation Officials mengklasifikasikannya sebagai “patah tulang kritis”. Artinya di dalamnya terdapat elemen yang kegagalannya diperkirakan akan menyebabkan sebagian atau seluruh jembatan runtuh, karena jembatan tidak memiliki komponen lain yang dapat menopang beban.

Program Inspeksi Jembatan Nasional dibuat setelah Jembatan Point Pleasant di atas Sungai Ohio runtuh pada tahun 1967, menewaskan 46 orang, ketika satu batang logam dalam rantai suspensi rusak. Standar diperketat setelah bagian 100 kaki dari Jembatan Sungai Mianus di Interstate 95 di Connecticut runtuh pada tahun 1983, menewaskan tiga orang. Keruntuhan terjadi setelah pengaratan yang menyebabkan bantalan luar tidak berfungsi.

Kebanyakan jembatan yang dibangun sejak pertengahan 1970-an memiliki desain redundan yang masih dapat menopang beban jika ada komponen yang rusak. Ini berarti bahwa jembatan dapat mengalami retakan besar tanpa risiko runtuh struktural.

Di CSU, kami menggunakan evaluasi probabilistik dan model komputer 3D canggih untuk melihat bagaimana retak fatik tumbuh di jembatan baja dua gelagar dan menilai potensi runtuhnya jembatan. (Girder adalah balok atau struktur horizontal yang menopang geladak jembatan.) Jembatan dua gelagar merupakan target kritis, karena hanya satu gelagar yang tersisa untuk menopang beban jika yang lain gagal.

Categories
ARTIKEL

MANFAAT MESIN JAHIT INDUSTRI

MESIN JAHIT INDUSTRI

manfaat mesin jahit industri

Manfaat mesin jahit industri, pertama dan terpenting, untuk menjahit, tetapi itu bukan batasan untuk kesenangan yang dapat Anda miliki. Panduan ini akan memberi Anda beberapa fakta, serta beberapa tip dan peringatan yang mungkin ingin Anda sampaikan ke sewist pemula yang sedang Anda latih. 

  1. KONTROL KECEPATAN

Sama seperti kebanyakan mesin domestik, Anda dapat mengontrol kecepatan melalui pedal kopling atau motor servo. Pengguna memiliki preferensi yang berbeda, dan seringkali bermuara pada versi mana pun yang paling sering digunakan pengguna untuk berlatih. Konon, banyak selokan baru akan mengaku bahwa belajar menggunakan pedal kopling bisa memakan waktu lebih lama daripada memahami cara kerja motor servo. Ini berarti bahwa Anda mungkin lebih baik memulai magang dengan mesin motor servo jika Anda membutuhkan mereka untuk belajar dengan cepat. 

  1. MELILITKAN GELENDONG

Saat ini, sebagian besar mesin jahit industri modern dapat melilitkan kumparan saat Anda menjahit, yang dapat mempercepat pekerjaan pada proyek menjahit Anda saat ini dalam jumlah yang wajar. Mesin yang berbeda memiliki petunjuk yang berbeda untuk menggulung spul, jadi pastikan Anda selalu membaca petunjuk saat menggunakan mesin yang tidak Anda kenal. 

  1. FINISHING JAHITAN

Tidak seperti dalam situasi rumah tangga, Anda mungkin tidak akan mengandalkan mesin lockstitch sederhana untuk menyelesaikan jahitan Anda dengan jahitan zig-zag kecuali itu adalah pilihan desain yang disengaja. Sebaliknya, Anda harus mempertimbangkan untuk berinvestasi dalam overlocker, yang juga dikenal sebagai serger, yang akan membungkus tepi bahan Anda dengan benang untuk mencegah terurai sambil juga menyediakan pakaian yang dibuat secara menyeluruh dan terlihat profesional.

  1. JAHIT BAHAN BERAT

Jika Anda memiliki pekerja atau magang baru yang sebelumnya hanya pernah menyodorkan tangan, mereka mungkin berasumsi bahwa mesin jahit industri dapat mengambil apa pun yang Anda lempar tanpa mengeluh. Namun, seperti yang diketahui oleh penjahit yang belum berpengalaman, Anda tetap harus berhati-hati saat menjahit dengan bahan yang berat. Misalnya, jika Anda merencanakan proyek yang mencakup kulit, pemandu profesional akan memperingatkan agar tidak menggunakan kaki biasa karena dapat menyebabkan kulit meregang. Dalam hampir semua kasus, gudang memiliki mesin yang dibuat khusus untuk menangani material yang lebih berat ini.

Ada kekhawatiran serupa mengenai jenis kain lain yang kurang umum sehingga mereka yang baru mengenal mesin harus diperingatkan, seperti saat mencoba menjahit melalui bulu (palsu atau lainnya), penting untuk mencoba memisahkan bulu di tempat tusukannya akan diatur. untuk menghindari menjebak rambut di bawah tusuk yang akan menyebabkan tusuk lepas jika untaian lepas dari bawah.

Dalam lingkungan industri, biasanya ada mesin yang berbeda untuk menangani tugas yang berbeda, daripada menggunakan berbagai aksesoris untuk mengelola semua pekerjaan, yaitu berapa banyak saluran pembuangan rumah tangga yang menyelesaikan proyek mereka.

  1. SIMPUL TAK DISENGAJA

Anda dapat membuat simpul pada jahitan Anda pada mesin jahit industri jika Anda tidak hati-hati. Beberapa alasan mesin Anda mungkin menyebabkan simpul pada jahitan Anda bisa jadi karena Anda memiliki tegangan bagian atas yang terlalu tinggi atau Anda menarik kain saat melewati mesin. Knot dapat mengganggu alur kerja, jadi mendapatkan teknik yang benar akan mengurangi jumlah waktu yang terbuang untuk melepasnya nanti.

manfaat mesin jahit industri

Ada banyak kesalahpahaman dan juga jebakan yang dapat dengan mudah dihadapi oleh para pemula, tetapi ada banyak kegembiraan yang bisa didapat dari menguasai mesin jahit industri. Menjahit di lingkungan ini memungkinkan pekerja untuk benar-benar menjadi ahli dalam aspek menjahit itu, daripada menjadi dongkrak domestik dari semua perdagangan.

Categories
Uncategorized

Hello world!

Welcome to BLOG MAHASISSWA UNIVERSITAS MEDAN AREA. This is your first post. Edit or delete it, then start writing!