Current Issue : October-December Volume : 2022 Issue Number : 4 Articles : 5 Articles
With the growing importance of the principle of sustainability, there is an increasing interest in the use of timber–concrete composite for floors, especially for medium and large span buildings. Timber–concrete composite combines the better properties of both materials and reduces their disadvantages. The most common choice is to use a cross‐laminated timber panel as a base for a timber–concrete composite. But a timber–concrete composite solution with plywood rib panels with an adhesive connection between the timber base and fibre reinforced concrete layer is offered as the more cost‐effective constructive solution. An algorithm for determining the rational parameters of the panel cross‐section has been developed. The software was written based on the proposed algorithm to compare timber–concrete composite panels with cross‐laminated timber and plywood rib panel bases. The developed algorithm includes recommendations of forthcoming Eurocode 5 for timber–concrete composite design and an innovative approach to vibration calculations. The obtained data conclude that the proposed structural solution has up to 73% lower cost and up to 71% smaller self‐weight. Thus, the proposed timber–concrete composite construction can meet the needs of society for cost‐effective and sustainable innovative floor solutions....
Comprehensive evaluation of the geological disaster risk of super long tunnels is significant for safety construction. In this paper, we establish a comprehensive evaluation system based on the cloud model and analytic hierarchy process (AHP) theory, considering four kinds of geological hazards, such as water and mud inrush, large deformation, rock burst, and collapse. Then, based on a super long highway tunnel of the Chizhou-Qimen expressway in China, the construction risk evaluation is carried out. The results show that the evaluation system can accurately judge the disaster risk level of the tunnel under different conditions surrounding a rock. The cloud model theory can realize the mutual transformation of qualitative indicators and quantitative indicators and avoid the problem of intense subjectivity of evaluation indicators. The evaluation system can be used as a new approach to evaluate tunnel risks in similar projects....
Relying on the project of the open-cut municipal tunnel undercrossing Ankang Freight V yard, the train dynamic response and seismic response of ultrashallow-buried rectangular tunnel of the lower interchange are studied, respectively, by combining the method of field measurement and numerical simulation. The results show that under the action of train vibration load, the dynamic stress response of the top plate midspan and the upper end of the side wall of the tunnel cross section directly below the rail is the most significant, and the dynamic stress response of the bottom plate is the smallest. Under the rare earthquake, the tunnel structure has large transverse deformation, in which the transverse displacement of the tunnel roof is the largest. At the same time, there is a large stress concentration at the variable section of the tunnel....
In this study, a contact surface constitutive model with zero-thickness unit and variable shear stiffness was improved based on the statistical damage constitutive model. The model parameters were derived by means of the shear stress-shear displacement curve of the pile-soil contact surface, and the model parameters under different normal stresses were obtained by the linear interpolation method. At the same time, the influence of the interpolation interval range on the model parameters was explored. The shear stiffness adjustment factor was introduced, and the improved pile-soil contact surface constitutive model was applied to the numerical simulation of pile-soil contact surface shear calculations using the fish language embedded in FLAC 3D, and the variation of monopile bearing characteristics and ultimate bearing capacity were investigated and analyzed. The results show that the improved contact surface constitutive model is able to reflect the nonlinear variation of shear stiffness, and that different normal stresses correspond to different fitting parameters, demonstrating the depth effect of the model. The accuracy of the model parameters reduces as the interpolation interval increases, and the interpolation results are more accurate when the interval range is smaller. The numerical model accurately simulates the pile-soil contact surface shear calculation and the monopile bearing calculation, and the simulation results of the ultimate pile bearing capacity are closer to the results computed by the equations in the Chinese code. At the same time, the variation law of pile axial force and pile lateral frictional resistance along the depth direction and the variation of pile ultimate bearing capacity under different working conditions are reasonable, which shows the validity of the contact surface principal structure model and the reasonableness of numerical calculation in this study....
The implementation of building information modeling (BIM) methodology in the construction industry has wide applicability with recognized benefits when designing, constructing, and operating buildings. To stay competitive in business, companies are urged to recruit professionals that offer brand-new knowledge and skillsets. To meet this demand, BIM training regarding the concept, range of applications, and tools available is required within the construction profession. A recent short course organized by the University of Lisbon, Portugal, actualized with the most relevant achievements in Master’s degree research, was offered to professionals in the industry, namely, architects and civil engineers coming from diverse engineering areas such as the environment, construction, maintenance, contracting and surveyors, and from patrimonial enterprises and public organizations, as well as city councils. The proposed action covers the areas of construction (conflict analysis, planning, and material quantity), structures (interoperability, analyses, and the transfer of information between software types), and the most recent heritage building information modeling (HBIM) perspectives. The methodology used was based on the presentation of case studies related to situations of conflict between disciplines, interoperability problems, and the structural rehabilitation of old buildings. The difficulties found in the course are mainly due to the heterogeneity of the participating population, who have different interests and specific perspectives. The participants followed the course with great interest and satisfaction, formulating several questions directed at the particular field of expertise of each professional. In general, the participants indicated a positive score, and changes in response to negative feedback will be adopted in future courses. The course aims to contribute to the dissemination of the potential of BIM in the design, construction, and refurbishment of historical buildings....
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