Iris Publishers Civil Engineering Open Access Journals

  Abstract On July 12, 2018, a large-scale landslide occurred in the Jiangdingya area, Nanyu Town, Gansu Province, China. According to remote sensing interpretation and field investigation, the landslide volume is about 480×104 - 550×104m3, which caused the Bailongjiang River to be blocked and the water level to rise, forming a dammed lake, flooding Nanyu Town. The landslide is characterized by chain disasters, which poses a serious threat to the ecological security of the upper reaches of the Yangtze River. In this paper, the catastrophic mechanism of Jiangdingya landslide is analyzed, and the stability of the slope is studied. According to the disaster characteristics, comprehensive safety control measures are put forward. The research results of this paper are of great significance to the prevention and control of chain disasters and the comprehensive treatment of slopes. Read More about this article: https://irispublishers.com/ctcse/fulltext/catastrophic-mechanism-and-stab...

  Abstract Modal parameters are able to characterize any structure uniquely. All the structural elements and the respective boundary conditions have a direct impact in all of the modal parameters (natural frequencies, damping ratios and mode shapes), making them suitable to detect damage along the structure. To this end, experimental identification of the modal parameters is necessary and must be conducted periodically. In the last decade, operational modal analysis has been developed to this purpose. It allows the identification of the modal parameter with the structures in operational conditions and using ambient excitation. Several improvements in the field were recently made with the computation of modal parameters uncertainties and with the automation in the identification process. Therefore, vibration-base structural health monitoring system is getting popular for critical civil structures such as bridges, high buildings and old constructions. Read More about this article:...

  Abstract Project monitoring and control processes are crucial aspects of project management. To perform an appropriate project tracking, Earned Value Analysis (EVA) has to be implemented to help the project managers to measure project performances. A tool to monitor and control the cost, time and work done of a construction project. Furthermore, it also provides an “Early Warning” signal for immediate corrective action. Thereby, in this study, some work items related to a completed real life construction project were evaluated according to the method of Earned Value and the result implies that the analysis can be very useful in project forecasting and decision making relevant to early warnings. Read More about this article: https://irispublishers.com/ctcse/fulltext/project-monitoring-and-early-warning-of-time-cost-overruns-in-earned-value-management.ID.000673.php Read More about Iris Publishers Google scholar Articles : https://scholar.google.com/citations?view_op=vie...

  Abstract Radon-222 and its progeny can accumulate in the lower floor premises and harm the people respiratory organs. One of the challenges for the construction industry is to provide indoor radon concentrations that are not much different from its concentrations in the outdoor air. The article proposes an approach to ensuring the buildings radon safety by the passive protective technologies. Its essence is in the determination at the design stage of the required radon protection characteristics of the building underground shell, which performs load-bearing functions and at the same time limits the radon flux from the soil air. Read More about this article: https://irispublishers.com/ctcse/fulltext/the-calculation-of-the-parameters-of-buildings-protection-from-radon.ID.000674.php Read More about Iris Publishers Google scholar Articles : https://scholar.google.com/citations?view_op=view_citation&hl=en&user=LoZ6uCQAAAAJ&cstart=20&pagesize=80&citation...

  Abstract The application of Fiber Bragg Grating (FBG) technology for purposes of diagnostic field testing on steel girder bridges is discussed in this paper based on the authors experience in field tests of highway bridges. The primary benefit of the FBG technology is the ability to have many sensors (strain gages) multiplexed in a single fiber optic line. In practice, the FBG system is problematic for field conditions of a typical highway bridge. In field tests, measured FBG data showed that the strain histories obtained for a load immediately above the girder of interest were accurate, but the accuracy of the strain histories decreases for adjacent girders as the transverse distance from the load increased. Moreover, protective measures are necessary for FBG systems to be utilized in highway bridge field testing. Read More about this article: https://irispublishers.com/ctcse/fulltext/discussion-of-fiber-bragg-grating-technology-applicability-on-diagnostic-field-testing-of-...

 Abstract This article describes the process of design, analysis, and manufacture of a modular, adaptable, and lightweight folding Bamboo dome. The study developed a new form-finding method with rigid scissors to simulated complex geometric forms to show rigid-bar deformation and using more uniform bars. The structure is composed of six flat semi-arches that fold through the scissor-type system reducing the size of the dome to facilitate is transport. Bamboo bars with a circular section are used as a main material for the structural arches. This research has been contextualized in the development and the form-finding process of curved surfaces with articulated bars. Félix Escrig’s projects have been utilized as the main reference, in particular, his method based on the regular polyhedron’s geometry, which allows obtaining the largest number of similar pieces. For this case study, a new approach to the regular polygon method is applied in the design process. The new methodology allo...

  Abstract A study on the effects of blast loads on tower-line coupling, single tower structure and tower-line structure system has been conducted and a variety of structural response variables have been compared. The modular and powerful finite element analysis software Dlubal- RFEM has been utilized for the blast-oriented linear implicit dynamic analysis of latticed transmission line structures covered in this study. The transient dynamic equilibrium equations of the tower have been directly solved by Newmark time integration method. Several study models from this work have indicated that there is up to nearly four-fold increase in support forces in uncoupled systems which subsequently greatly influence the planning, selection, design and detailing of support systems for such structures. Read More about this article: https://irispublishers.com/ctcse/fulltext/response-of-coupled-power-transmission-tower-line-systems-subjected-to-blast-loads.ID.000684.php Read More about Iri...

  Abstract The problem of increasing the bearing capacity of foundations is always an urgent problem in modern geotechnical construction. With additional increased external loads on existing restraint structures, the use of traditional technologies to ensure their stability is not always justified. Often there is an urgent need to use non-standard methods of strengthening the bases. There are frequent cases of using existing retaining reinforced concrete structures for new additional loads from newly erected objects. In such cases, the use of ERT drill piles and soil ERT anchors in most cases successfully solves many complex geotechnical problems of strengthening overloaded bases. Read More about this article: https://irispublishers.com/ctcse/fulltext/the-case-of-strengthening-the-base-of-a-deformed-retaining-wall.ID.000686.php Read More about Iris Publishers Google scholar Articles : https://scholar.google.com/citations?view_op=view_citation&hl=en&user=LoZ6uCQA...

  Abstract What is the contribution of circular economy in the effort to meet Paris agreement and slow down global warming? How circular is our planet, and which is the circularity gap in order to meet the Paris agreement? What is the role of cities in circular green transformation? This short communication communicates briefly finding of the URGE: Circular Building Cities Network that is financed by the URBACT programme, aiming to promote the role of cities in boosting circularity, specifically in the construction sector. Read More about this article: https://irispublishers.com/ctcse/fulltext/circular-economy-in-the-building-sector-experience-from-the-urge-circular-building-cities-action-planning-network.ID.000689.php Read More about Iris Publishers Google scholar Articles : https://scholar.google.com/citations?view_op=view_citation&hl=en&user=LoZ6uCQAAAAJ&cstart=20&pagesize=80&citation_for_view=LoZ6uCQAAAAJ:-_dYPAW6P2MC

  Abstract Pipelines are an economical means of transporting oil and gas. A commonly encountered performance issue with such structures, however, is their susceptibility to buckling under hydrostatic and hydrodynamic pressure loads. In such a failure scenario, the pipe will suddenly collapse under the action of the loads and can render the transport structure as ineffective. The engineering design of pipes must therefore account for the action and magnitudes of such anticipated service loading, referred to as buckle propagation pressure, in achieving an adequate and sound performance. As for the notion of economy, since buckle propagation pressure is closely related to the pipe wall thickness, it has a direct bearing on overall project costs. In this study, to simulate in situ conditions of subsea pipelines, only uniform hydrostatic pressure was taken into consideration as the source for loading. A finite element method (FEM) model was then used to examine the buckling modes on pip...

  Abstract Based on continuum topology optimization, a subdomain approach for achieving optimal pile layout in a composite pile foundation (CPF) is presented. In general, the computational time is excessively long when the span of a CPF is far greater than the depth of pile and the nonlinearity of soils and soil-pile contact are considered. To reduce computational time, we suggest dividing the original pile foundation into a number of subdomains. Only a few representative subdomains (RSs), such as the corner representative subdomain (CRS), side representative subdomain (SRS), and inner representative subdomain (IRS), are required to find the optimal pile layout through topology optimization. In optimization, the pile volumes, maximum settlement, and settlement uniformity of foundation surface are considered simultaneously. Numerical experiments are presented, and the validity of the algorithm is verified. In the present method, a CPF with an initial uniform layout of piles of the s...

  Abstract The problem of increasing the bearing capacity of a foundation is always an urgent one in today’s geotechnical construction. With significant loads transferred to foundations, the use of traditional technologies is not always justified. There is often an urgent need to use non-standard methods of strengthening the foundations. In many cases, the geotechnical situation is aggravated by the presence of weak underlying layers with unstable physical and mechanical characteristics in the engineering-geological sections. When reinforcing such foundations with the help of traditional piles, the latter can receive negative friction, which significantly reduces their bearing capacity on the ground, sometimes reaching zero values. This can lead to additional precipitation of objects being erected and objects already erected in the zone of geotechnical influence. The use of Electric Discharge Technology (EDT) piles in most cases successfully solves many complex geotechnical problem...

  Abstract Concrete structures made with traditional black steel reinforcement are deteriorating at an alarming pace due to corrosion effects. Many research institutes across the globe are spending lots of resources to overcome this problem by replacing steel reinforcement with fiber reinforced polymer (FRP) rebars because these bars are corrosion resistant. FRP rebars are a product of composite materials with raw materials made from sized fibers and thermoset polymeric resin. The fibers can be made from various materials and glass fibers have been most dominant in the US market due to historical developments. However, basalt fiber reinforced polymer rebars (BFRP rebars) are now becoming more popular. With a significant increase in demand for such materials, the number of manufacturers increased notably over the past two decades. Because the production of FRP rebars has not been standardized yet, a wide range of products with several different material characteristics and mechanica...

  Abstract Compaction parameters determination in the laboratory require considerable time and effort that can be saved by using empirical correlations at the early stages. This paper introduces some efforts to predict the compaction properties of soils using the index test results. Apart from the experimental result, the result from other literature have also been considered in the analysis here. Different statistical investigation such as histogram, ACF, PACF, kernel function, correlogram and cross correlogram are used to find the relationship of liquid limit, plastic limit and plasticity index with optimum moisture content and maximum dry density. Regression analyses are done with support vector machine algorithm. The best R squared value found from the predicted equation is 0.86 for optimum moisture content and 0.91 for maximum dry density. Keywords:  Prediction; Optimum moisture content; Maximum dry density; Compaction parameters; Support vector regression Read More about...

  Abstract Although contemporary information and computer technologies enable researchers, designers, and engineers to collect large amounts of data, current approaches for sharing data remain limited by concerns such as interoperability, shareability, data size, transport costs, and privacy. These concerns often prevent or confound the development of reliable and accurate building performance simulations. In an effort to overcome these concerns, we envisioned a complementary approach, called the Virtual Information Fabric Infrastructure (VIFI) approach, where data owners share distributed, fragmented data in a manner that does not require the movement of raw data and data users utilize these data for analysis by transporting analytic computation to the data. The VIFI approach presents new opportunities to conduct building performance simulations. Through two case studies, we demonstrated a new computational framework based on VIFI to support an open and collaborative cyberinfrastr...

  Abstract Computational geomechanics is the field of computational mechanics where geo-engineering systems are analyzed using the prinCurrently there is a demand for CCS of large quantities of CO 2  associated with CH 4  in the pre-salt offshore oil fields in Brazil. The pre-salt reservoirs have as caprock 2000 meters of continuous rock salt. Rock salt is a special geomaterial. It has negligible permeability and porosity, is able to support very high stresses, develops the self-healing effect, fractures will heal only with time and a good geomechanical project can design very large openings in the salt body. In Brazil the rock mechanics and computing modeling related to underground excavations in salt rock started in the years 1970´s with very complex challenges, starting with the project of an underground mining of sylvinite (potash ore) overlying tachyhydrite, a very weak salt rock, solving the challenges of the solution mining of salt caverns, for brine production, in...

  Abstract The sustainable development goals (SDGs) were agreed by 195 nations on United Nation (UN) climate change conference in Paris 2015. The agreement was about climate actions to reduce the global warming and reinforcing countries strengths in dealing with climate change phenomenon by means of 17 goals. Researchers and engineers can have a significant contribution in successfulness of the Paris agreement. In particular, ground improvement in geotechnical engineering can have an effective role in promoting goal 12 of the UN SDGs to ensure sustainable consumption and production pattern. One of the key targets for this goal is substantially reduction of the waste production by means of recycling and reuse by 2030. Given the increasing trend of the world’s population, as such, the production and consumption rates have an increasing trend which makes achieving this goal so challenging. Some manufacturing industries generate by-products in addition to their end-products that usuall...

  Abstract The quality problems encountered in concrete structures appear at different stages of the construction of works, it is for this reason that for a long time there has been an increased demand for more precise and, at the same time, more flexible methods of concrete quality assessment. This paper presents some notions concerning the Schmidt rebound hammer test which is one of the non-destructive methods most used for the recognition of the condition of building structures. This test is quick and easy, it makes it possible to control the quality of the construction and to indirectly measure the compressive strength of concrete in situ. The rebound hammer calibration procedure was detailed on an example by presenting the different steps. The influence of several factors affecting the rebound hammer test, whether related to the properties of concrete or otherwise, was were presented. Indeed, Surface texture, concrete humidity, type of aggregates, cement type and carbonation o...

   Iris Publishers - Scholarly Open Access Journal of Civil and Structural Engineering Causes of Construction Delays in Different Buildings Typology in Portugal Abstract The construction represents the sector with the higher impact in the world economy, representing 13.4 %. This sector, crucial to the socioeconomic stability of a country, has been several affected due to the successive construction delays in the design as well as execution phases. Additionally, in comparison with other sectors, the construction industries present lower receptivity in the development of new methodologies and technologies to increase the competitiveness as well as workers incomes and profits increasing the attention from the industry and academia. This study focusing the identification of the constructions processes, which leaves to their delays. Thus, three different buildings typology use were studied (in a real ambient), to identify the delays by groups, type and category to achieve a deep un...