Construction Site Conditions Research Articles

The Research Progress on Surveying Technology of Architecture Construction

<p>Various engineering project construction must go through planning and design, architecture construction, operation management and other stages. Each stage should carry out relevant measurements, including measuring project during the construction phase and initial operational phase which called construction surveying. Engineering Surveying is the key work during construction of architecture projects, which affecting the construction quality and operation process of architecture objects. A detailed surveying work should be conducted at the early stage of official start of architecture engineering, in order to grasp the geological conditions of construction site, and avoiding the occurrence of various diseases phenomenon during post-operation. Therefore, coordination between engineering units is needed to complete the surveying of architecture project together</p>

The Research Progress on Surveying Technology of Architecture Construction

<p>Various engineering project construction must go through planning and design, architecture construction, operation management and other stages. Each stage should carry out relevant measurements, including measuring project during the construction phase and initial operational phase which called construction surveying. Engineering Surveying is the key work during construction of architecture projects, which affecting the construction quality and operation process of architecture objects. A detailed surveying work should be conducted at the early stage of official start of architecture engineering, in order to grasp the geological conditions of construction site, and avoiding the occurrence of various diseases phenomenon during post-operation. Therefore, coordination between engineering units is needed to complete the surveying of architecture project together</p>

CHARACTERIZATION OF THE INTERFACE BETWEEN FRESH CONCRETE AND FORMWORK

Concrete surface quality is generally linked to the development conditions of concrete close to the formwork. This work aims to study the influence of the nature of release agent and the quantity of fine elements on the chemical interactions at the concrete/oil/formwork interface. Five concretes were prepared at 28, 30, 32, 34, and 36% of paste to study the influence of paste volume on the friction between formwork and fresh concrete. The friction tests were performed using an apparatus which can reproduce the same conditions of construction sites. In addition, a physicochemical investigation was achieved to identify the effect of fine elements on the ability to form the interstitial mediums at the interface. The formation of soap in the vicinity of the formwork surfaces was also studied as a function of the content and the nature of oils. The results showed that the friction between fresh concrete and formwork depends on the pore solution content present at the interface.

Estimation on Clamping Force of High Strength Bolts Considering Temperature Variable of Both Site conditions and Indoor Environments

The torque shear high strength bolt is clamped normally at the break of pin-tail specified. However, the clamping forces on slip critical connections do not often meet the required tension, as it considerably fluctuates due to torque coefficient dependent on lubricant affected temperature. In this study, the clamping tests of torque shear bolts were conducted independently at indoor conditions and at construction site conditions. During last six years, temperature of candidated site conditions was recorded from to . The indoor temperature condition was ranged from to at each interval. As for site conditions, the clamping force was reached in the range from 159 to 210 kN and the torque value was from 405 to . The range of torque coefficient at indoor conditions was analyzed from 0.126 to 0.158 while tensions were indicated from 179 to 192 kN. The torque coefficient at site conditions was ranged from 0.118 to 0.152. Based on this test, the variable trends of torque coefficient, tension subjected temperature can be taken by statistic regressive analysis. The variable of torque coefficient under the indoor conditions is while it reaches at actual site conditions. When the indoor trends and site conditions is combined, the modified variable of torque coefficient can be expected as . and the modified variable of tension can be determined as .

Factors affecting the thermo-chemo-mechanical behaviour of massive concrete structures at early-age

Different factors related to construction site conditions must be accounted for when designing concrete massive structures in order to accurately predict the cracking risks at early-age. Detailed descriptions of the thermal and mechanical boundary conditions as well as analyses accounting for the coupling between damage and creep may lead to computationally expensive simulations campaign. On the other hand, simplified modelling strategies have been extensively used but may not capture accurately key aspects of such analysis. Based on a previous chemo-thermal analysis by Honorio et al. (Eng Struct 80:173–188, 2014), the present study focuses on the mechanical behaviour of a specific structure by making use of a coupled thermo-chemo-creep-damage model. Simplified modelling strategies to treat the external restraints and some thermal boundary conditions are compared to more realistic ones. The risks of cracking are assessed by means of a cracking index (CI) and a damage model. Restraint conditions in which the ground is not represented leads to cracking risks in different zones if compared to the case with the ground. It is shown that, the ambient temperature affects directly the tensile stresses reached and the oscillation of the temperature within a day may play a non-negligible role. The effect of damage and its coupling with creep are analysed, and a strong influence of the corresponding coupling parameter on the cracking initiation and propagation is observed.

A comparison of economic feasibility and emission of carbon dioxide for two recycling processes

In order to effectively recycle Construction and Demolition, this study evaluates and quantifies the economic feasibility and emission of carbon dioxide for two recycling processes: on-site recycling process and process of a private recycling center. The results show that recycling costs were strongly influenced by the transport distance, the construction site conditions, and the amount of waste concrete to recycle, while emissions of carbon dioxide of the two recycling processes was mainly affected by the transport distance. On-site recycling process at the construction site cost only 63.8% as much and emitted only 33.6% as much carbon dioxide as the process at a private recycling center. Using sensitivity analysis, this study found that the unit recycling cost of on-site recycling process had little impact on the installation and dismantling costs of on-site recycling facilities when there was more than 10,000 metric tons of waste concrete to recycle. The process of a private recycling center emitted more carbon dioxide than on-site recycling process when the transport distance exceeded 10 km.

Study on Concrete Construction Technology of High-Rise Building

This paper introduces the features and key points of construction of high-rise buildings. Combined with the practical application, the technology of concrete construction is put forward, as well as the control method of concrete pouring quality. According to the specific conditions of construction site, the construction method of foundation from shallow to deep is adapted. The different placement scheme and technical measures are made.

도로공사 공정계획을 위한 공정 로직 및 건설장비 효율화 방안

Highway construction is a combination of linear, repetitive, and highly equipment intensive operations. Various types of construction equipment are deployed to ensure undisrupted performance of construction, and thus productivity improvement and cost-saving can be achieved through well-thought-out planning. The selection of construction equipment is dependent upon construction sequence, site conditions, and construction methods. In the process of planning, management should consider various types of construction methods per each type of construction operation. Also, management should map out proper construction equipment operation plan that takes the construction duration and cost measures into consideration. However, limited availability of historic data from the similar types of operations has been a stumbling block to proper construction planning, making the operations performed based upon experience and intuition guided by rules-of-thumb. As a consequence, the planing phase rarely provided an adequate validity in the implementation phase. The researchers developed a process logic for each construction type that management can utilize from early phase of highway construction planning process. Moreover, derived the construction equipment combination optimized for efficiency by using the process simulation technique. The developed method is expected to be useful for the decision-making process that aims to evaluate efficiency of various process plans and to ensure optimal selection of construction equipment for highway construction projects.

Particle bee algorithm for tower crane layout with material quantity supply and demand optimization

Abstract The tower crane layout (TCL) problem, a typical construction site layout (CSL) problem, is currently used in a wide range of construction projects and site conditions. The tower crane is a key facility used in the vertical and horizontal transportation of materials, particularly heavy prefabrication units such as steel beams, ready-mixed concrete, prefabricated elements, and large-panel formwork. Matching the location of tower cranes to material supply and engineering demands is a combinatorial optimization issue within the TCL problem that is difficult to resolve. Swarm intelligence (SI) is a popular artificial intelligence technique that is used widely to resolve complex optimization problems. Various SI-based algorithms have been developed that emulate the collective behavior of animals such as honey bees (bee algorithm, BA) and birds (particle swarm optimization, PSO). This study applies the particle bee algorithm (PBA), a hybrid swarm algorithm that integrates the respective advantages of honey bee and bird swarms, to the TCL problem. The performances of PBA, BA, and PSO are compared in terms of their effectiveness in resolving a practical TCL problem in construction engineering. Results show that the PBA performs better than both the BA and PSO algorithms.

조경업체에서의 철쭉재배품종의 혼선 및 이용실태 분석

국내 조경용 철쭉재배품종(이하, 철쭉류)에 대한 조경업체 종사자(설계자 및 시공자, 생산자)간 철쭉류별 혼선 및 이용실태를 분석하였다. 조달청 등의 고시기관에서 고시한 철쭉류 명칭대로 생산농가에 주문 시 어떤 철쭉류가 배달되는지 조사해 철쭉류의 혼선 실태를 분석했다. 또한, 최근 완공된 아파트 3곳의 식재설계 도면에서 철쭉류의 식재설계 상황, 도면상의 철쭉류와 실제 식재된 철쭉류와의 일치 여부를 조사하였다. 고시된 철쭉류 명칭대로 주문한 결과, 영산홍 명칭으로는 베니, 쓰리, 대왕의 3가지 철쭉류가 배달되었고, 자산홍의 명칭으로는 자산홍, 한철의 2가지 철쭉류가 주문되었다. 영산홍은 베니, 쓰리, 대왕 등을 통칭하는 명칭으로 생산자와 주문자간 혼선을 빚었다. 자산홍의 경우에는 한철품종과 형질이 유사하여 생산자가 재배품종을 명확하게 구분하지 못하였거나, 주문자가 쉽게 구분하지 못해 두 재배품종을 구분하지 않고 보냈을 가능성도 있다. 식재설계 도면상 철쭉류 명칭은 고시기관에서 고시한 철쭉류 명칭을 사용하거나, 철쭉, 영산홍 등의 포괄적이고 불분명한 명칭으로 기재되었다. 식재설계 도면에 기재된 철쭉류는 실제 시공현장에서는 전혀 다른 철쭉류가 식재된 경우가 많았다. 이러한 원인은 설계자가 식재설계 도면에 정확한 재배품종명을 기재하지 않고, 시공자는 각 철쭉류의 분류 특성을 정확하게 인지하지 못하고, 비슷한 꽃색이나 구입이 용이한 철쭉류를 시공 현장조건에 맞게 심기 때문일 것이다. This study was conducted to examine the state of confusion about those azalea cultivars(hereinafter, Azalea Cultivars) that are used among practicians in landscaping businesses(designers, constructors, and producers). Which Azalea Cultivars would be delivered when they were ordered to producers using the names of Azalea Cultivars notified by the Public Procurement Service. In addition, the situations of azalea cultivar planting designs in the planting design drawings of three apartments completed recently and whether the Azalea Cultivars on the design drawings were the same as those Azalea Cultivars that were actually planted were examined. When Azalea Cultivars were ordered using the notified names, three Azalea Cultivars; Beni, Three, and Daewang were delivered for the name Yeongsanhong and two Azalea Cultivars; Zasanhong and Hancheol were delivered for the name Zasanhong. Yeongsanhong was perceived as a common name of Beni, Three, and Daewang by producers. Therefore, this caused confusion between producers and purchasers. In the case of Zasanhong, as the traits of Zasanhong are similar to those of the cultivar Hancheol, the producers or purchasers might have been unable to clearly distinguish between the cultivars and thus two cultivars might have been delivered without being distinguished from each other. The names of Azalea Cultivars used in planting design drawings were the names notified by the notifying agencies or comprehensive and unclear names such as azalea and Yeongsanhong. Completely different Azalea Cultivars from those written in planting design drawings were planted in actual construction sites in many cases. These situations should have occurred because designers did not write accurate cultivar names in planting design drawings and constructors could not accurately perceive the classification characteristics of individual Azalea Cultivars but planted those Azalea Cultivars with similar flowers colors or those that could be easily bought to fit the conditions of construction sites.

Static and Dynamic Analysis of Railway Reinforced System with Cross-Beams

To fulfill the design requirement of railway reinforced system with cross-beams, the model for the static analysis of the railway reinforced system is optimized, the dynamic response is calculated by the vehicle-rail interaction method, the standards of both static and dynamic analysis are established, and the calculation results of many cases with different parameters are evaluated. It is found that, compared with simplified model, the optimized model simulated the conditions of construction site better, so that results are improved; the acceleration and the offloading factor of reinforced system is obtained by the dynamic analysis, whose vibration and resonance phenomenon can be simulated. The calculated result and the railway reinforcement design are safer by adopting the proposed standard in both static and dynamic analysis.

Vision-based material recognition for automated monitoring of construction progress and generating building information modeling from unordered site image collections

Automatically monitoring construction progress or generating Building Information Models using site images collections – beyond point cloud data – requires semantic information such as construction materials and inter-connectivity to be recognized for building elements. In the case of materials such information can only be derived from appearance-based data contained in 2D imagery. Currently, the state-of-the-art texture recognition algorithms which are often used for recognizing materials are very promising (reaching over 95% average accuracy), yet they have mainly been tested in strictly controlled conditions and often do not perform well with images collected from construction sites (dropping to 70% accuracy and lower). In addition, there is no benchmark that validates their performance under real-world construction site conditions. To overcome these limitations, we propose a new vision-based method for material classification from single images taken under unknown viewpoint and site illumination conditions. In the proposed algorithm, material appearance is modeled by a joint probability distribution of responses from a filter bank and principal Hue-Saturation-Value color values and classified using a multiple one-vs.-all χ2 kernel Support Vector Machine classifier. Classification performance is compared with the state-of-the-art algorithms both in computer vision and AEC communities. For experimental studies, a new database containing 20 typical construction materials with more than 150 images per category is assembled and used for validation. Overall, for material classification an average accuracy of 97.1% for 200×200 pixel image patches are reported. In cases where image patches are smaller, our method can synthetically generate additional pixels and maintain a competitive accuracy to those reported above (90.8% for 30×30 pixel patches). The results show the promise of the applicability of the proposed method and expose the limitations of the state-of-the-art classification algorithms under real world conditions. It further defines a new benchmark that could be used to measure the performance of future algorithms.

무주 태권도원 현장 색채계획 시공단계 프로세스 적용사례연구

In order to maintain and protect professionalism in color planning, the present study examined the process at the time of realization of color through color inspection and supervision in the actual construction site and suggested plans for improvement. Reflecting the characteristics that the governing body of the construction site is not a private person but an organization, the present study aims to provide institutional measures so that the supervisor of color construction at the actual site of construction can propose concerns related to proper construction at the right time, and the matters cannot be decided from the perspective of a layman. The institutional measures are proposed through the case of application of a process at the construction stage of the color planning at the construction site of Muju Taekwondo Park. First, the process clarified where the responsibility lies by specifying special conditions concerning color inspection on the field guide and color contract. Second, the sample for building materials was selected after obtaining it from a company capable of supply and is appropriate for the planned unit cost so that it could play an important role in realizing colors at the stage of basic design. Third, the process of construction was ensured not by temporary selection of colors but by continuous approval of colors in consideration of the conditions of construction site through letter of approval of color at each stage and point of time. Fourth, coordination of various color elements of other fields including landscape, interior, and electricity ensured construction of the whole structure in one color concept. Fifth, color inspection through the mock up of the site will minimize erroneous construction and reconstruction and prevent decrease in productivity. Sixth, this study also suggested more comfortable and positive color environment through evaluation by experts and users. The researcher of this study expects that color experts actively participate in the stage of construction to contribute to improvement of the color environment.

Simulation of scheduling logic using dynamic functions

Since the late 1950s, researchers have studied the soft logic of scheduling, in particular the precedence constraint between activities used to compute the critical path. However, by proposing only external constraints and simulating work production through lags, the precedence logic lacks precision. These gaps diminish the reliability of the schedule and impair the internal monitoring of activity interdependencies. Chronographic logic addresses such limitations by introducing the internal division and proposing internal monitoring as a function of production. This paper proposes the concept of probabilistic production-based dynamic functions which would replace internal divisions with a mathematical function that permits the tracking of the dynamic interdependencies between two in-progress activities. A case study compares the overall schedule calculation using traditional precedence logic with the dynamic production-based function. This simulation was designed to investigate the overall impact on the critical path and the criticality of each activity. The result is a new method of implementing scheduling logic that takes into account the impact of the internal changes of workload and allows the use of internal margins. These self-adaptations provide a better simulation of construction-site conditions which help to produce more realistic results.

Accuracy assessment of Ultra-Wide Band technology in tracking static resources in indoor construction scenarios

Abstract The use of Ultra-Wide Band (UWB) tracking systems for construction site applications has attracted the attention of researchers in recent years. However, to enable an effective application, it is important to establish the accuracy of its location estimation and its performance under sub-optimal conditions of construction sites. Expanding on previous research, this research studied the performance of an UWB tracking system in static mode under conditions that can commonly occur on construction sites, namely: the presence of metal objects that reflect UWB signals; best signals being blocked by other objects; tracking metal objects; removing the timing cables; tracking multiple tags simultaneously, and decreased number of receivers. A series of experiments were conducted in which the impact of each condition was simulated by changing a variable. The accuracy and the relative error of location estimations for each experiment were calculated. With one exception, an accuracy of less than a meter was achieved in all the experiments.

System dynamics-based strategies to diffuse construction VE in the public sector

In construction, frequent contract changes and budget overages occur due to uncertain construction site conditions, schedule delays, and cost fluctuation. However, it has been demonstrated that it is possible to reduce construction costs through creative alternative solutions. For instance, through the implementation of the “Enforcement Decree of the Budget and Accounts Act” in 1980, the Korean government has attempted to enhance the construction process by distributing saved costs to contractors. However, Korea’s “Technology Development Rewarding System,” which is a regulation to activate Value Engineering (VE), has yielded tenuous results with only 5 successful cases. Through an examination of previous research and expert surveys on VE, this study identifies the predominant factors that influence the implementation of a Value Engineering Change Proposal (VECP) system. These variables are then divided into 5 categories: (1) design quality; (2) type of ordering system; (3) contract change; (4) attractiveness of VECP to contractors; and (5) attractiveness of VECP to owners. Furthermore, while previously proposed strategies, such as controlling the sharing rate, have been based on fragmentary analysis, this study deploys a System Dynamics (SD) approach to comprehensively analyze these variables and their causal relationships, and subsequently present 5 strategies to diffuse VECPs in the public sector. Finally, through a case study, this research proposes the practical implementation of the SD methodology for the development of government and company VE policy. Ultimately, this research aims at presenting strategies that will induce the government to revise their VE policy.

시스템 다이내믹스를 이용한 터널공사비 모델 개발

도로건설공사의 주요 구조물인 터널의 경우 건설지역, 지반 환경, 공법 등 다양한 변수에 의해 공사비가 결정된다. 그러나 NATM 터널 초기 공사비를 결정하기 위한 모델에 대한 연구는 부족한 실정이다. 따라서 본 논문은 시스템 사고를 활용하여 터널공사비 예측을 위한 모델을 제시하였다. 기존 문헌 조사를 통해 터널공사비의 영향요인을 파악하고 영향 요인간 상관관계를 고려하여 터널공사비 인과지도를 작성하였다. 그리고 터널공사의 내역서를 활용하여 터널 길이와 굴착량, 암질 등에 의한 터널공사비 변화정도를 분석하였다. 본 연구를 통해 다양한 영향요인을 고려한 NATM 터널공사비 예측에 대한 대안을 제시할 수 있을 것으로 기대한다. Construction cost of tunnel is decided on construction area, site conditions, and construction methods. However, there is few research on developing models to estimate early construction costs. Therefore, this paper presents a model for early estimation tool for NATM tunnel using system thinking. The effect factors for tunnel construction cost were defined and the causal map is developed. Then empirical case analysis were performed to identify the cost difference due to tunnel length, excavation volume, and rock quality. The proposed model would be an alternative to estimate early construction cost of NATM tunnel.

Application of TSP in Construction of Qiupi Tunnel

The accuracy of TSP in tunnel geological prediction system is restricted to the conditions of construction site. In order to improve the accuracy of the prediction result, it is necessary to improve the collection accuracy. This article is for the angle to improvement of focal points, charging structure, optimizing the explosive charge, improvement of the detection holes for receiving conditions to improve the data precision. So that the focal point detonating degree guarantees at a higher level, the accuracy of the data is relatively well, and the interpretation results are more accurate.

Formwork System Selection Model for Tall Building Construction Using the Adaboost Algorithm

In a tall building construction with reinforced concrete structures, the selection of an appropriate formwork system is a crucial factor for the success of the project. Thus, selecting an appropriate formwork system affects the entire construction duration and cost, as well as subsequent construction activities. However, in practice, the selection of an appropriate formwork system has depended mainly on the intuitive and subjective opinion of working level employees with restricted experience. Therefore, in this study, a formwork system selection model using the Adaboost algorithm is proposed to support the selection of a formwork system that is suitable for the construction site conditions. To validate the applicability of the proposed model, the selection models Adaboost and ANN were both applied to actual case data of tall building construction in Korea. The Adaboost model showed slightly better accuracy than that of the ANN model. The Adaboost model can assist engineers to determine the appropriate formwork system at the inception of future projects.

Research on the Key Technology in Steam Curing for 32m Simple-Supported Box Girder of High-Speed Railway

In the process of steam curing to high-speed railway’s simply-supported box girder, there are some problems must be faced such as the difficulty to determine steam curing system and to achieve automatic temperature control. With the construction site conditions of simple-supported box girder in Longwang beam field which is located on Shijiazhuang-Wuhan (Shi-Wu) section of Beijing-Guangzhou high-speed railway, the paper proposes the appropriate steam system for simply-supported box girders, determines the appropriate equipments, explores the temperature control system in the process of steam curing to the simply-supported box girder's concrete, and takes the temperature test of steam curing in the field. Results show that, the steam curing technology in this paper can increase the production efficiency of beam in production site, and effectively guarantee the prefabricated quality of simply-supported box girder.