Current Issue : October-December Volume : 2025 Issue Number : 4 Articles : 5 Articles
In this paper a new generalized fractal equation for studying the behaviour of self-similar beams using the Timoshenko beam theory is introduced. This equation is established in fractal dimensions by applying the concept of fractal continuum calculus Fα-CC introduced recently by Balankin and Elizarraraz in order to study engineering phenomena in complex bodies. Ultimately, the achieved formulation is a fourth-order fractal single equation generated by superposing a shear deformation on an Euler–Bernoulli beam. A mapping of the Timoshenko principle onto self-similar beams in the integer space into a corresponding principle for fractal continuum space is formulated employing local fractional differential operators. Consequently, the single equation that describes the stress/strain of a fractal Timoshenko beam is solved, which is simple, exact, and algorithmic as an alternative description of the fractal bending of beams. Therefore, the elastic curve function and rotation function can be described. Illustrative examples of classical beams are presented and show both the benefits and the efficiency of the suggested model....
The disc-buckle scaffold system demonstrates significant advantages in prefabricated construction applications, particularly in terms of installation efficiency, load-bearing capacity, and standardization. Guangzhou Construction Group Co., Ltd., a leading enterprise in promoting prefabricated building development in Guangdong Province, China, has collaborated with the Guangdong University of Technology to develop an innovative disc-buckle scaffold system. The main difference between different scaffolds lies in the connection part of the joint. The mechanical behavior of scaffold joint plays a critical role in determining the structural integrity of the entire scaffolding system. So, the novel disc-buckle scaffold proposed in this paper is mainly new in the joint. Finite element simulation based on the test results is employed to study the performance of the novel scaffold joint in this paper. The results show that the newly developed scaffold joint exhibits superior mechanical performance, characterized by a bending stiffness of 34.5 kN·m/rad. The joint demonstrates maximum tensile and compressive bearing capacities of approximately 108 kN and 70 kN in the transverse direction, respectively. Furthermore, the joint’s maximum shear bearing capacity exceeds 180 kN, surpassing the buckling critical force of the vertical steel pipe and satisfying all strength requirements. The scaffold joint exhibits robust hysteresis characteristics, and the wedge-shaped connection mechanism maintains consistent stiffness and load-bearing symmetry under both positive and negative bending moments. The proposed disc-buckle steel scaffold joint features a minimal number of components, achieving an optimal balance between structural performance and economic efficiency....
Climate change amplifies heat wave effects on outdoor thermal comfort by increasing their frequency, duration, and intensity. The urban heat island effect worsens heat risks in cities and impacts resilience. Nature-based solution (NBS) with tree plantation was reported as an effective mitigation measure. This simulation study, by the well-validated ENVI-met model, aimed to investigate the impact of different tree planting strategies and building parameters on urban heat risk mitigation and microclimate during a typical hot summer day. Hypothetical skyscrapers and super high-rise buildings were assumed in the study site located in southern China. Adopting meteorological inputs from a typical year, the simulation results revealed that both mean radiant temperature (Tmrt) and physiological equivalent temperature (PET) were elevated (Tmrt > 60 ◦C and PET > 50 ◦C) in early afternoon in sunlit areas. Three mitigation approaches with different tree planting locations were investigated. While all approaches demonstrated effective cooling (PET down to <35 ◦C) in the proximity of trees, a superior approach for mitigating the heat risks was not evident. Within the building array, the shade of bulky structures also lowered Tmrt and PET to a thermally comfortable level in the late afternoon. Combining open-space tree planting with optimized building designs is recommended to mitigate heat risks and enhance urban resilience while promoting outdoor activities and their health benefits....
This study analyzes the deformation and internal force changes of the main tunnel during the cutting process of the pipe jacking method for cross passages. A combination of field monitoring and numerical simulation was used to investigate a construction case of the pipe jacking method for the cross passage of Zhengzhou Metro Line 12. The study provides an in-depth analysis of the stress characteristics of the main tunnel structure during the segment-cutting process. The research findings indicate that during the pre-support stage, the internal support system helps to disperse external water and soil pressure, thereby reducing the internal forces and deformation of the tunnel. In the segment-cutting stage, the horizontal diameter of the main tunnel near the hole location gradually increases, while the vertical diameter decreases. At the same time, the stress on the bolts also rises, with the circumferential bolt stress exceeding that of the longitudinal bolts, eventually approaching their yield strength. The upper and lower ends of the tunnel opening are cut to form cantilever ends, leading to inward converging deformation. This deformation causes the internal forces to disperse toward both sides of the opening, resulting in a noticeable increase in internal force at the 90◦ position of the semi-cutting ring. The research findings provide a theoretical reference for understanding the deformation patterns and internal force transfer mechanisms of the main tunnel structure during the construction process of cross passages using the pipe jacking method....
Many urbanised areas of the Apennines, in Italy, have complex soil stratifications. A typical example is the outskirts of the city of L’Aquila, which is founded on highly heterogeneous soil layers and was severely affected by a strong earthquake in 2009. In such conditions, shear wave velocity profiles (VS) obtained from in situ tests such as the Seismic Dilatometer Marchetti Test (SDMT) provide reliable analyses of the local seismic response. This article presents the mono-dimensional (1D) and two-dimensional (2D) seismic response analyses conducted to characterise the soil foundation of the hospital complex and adjacent university buildings in L’Aquila before their seismic retrofitting. This study emphasises the importance of accurate soil characterisation prior to repair interventions, especially in deposits where there are VS inversions and in the presence of geometrically irregular and large structures. Under these conditions, estimating the motion amplitudes of the deposit’s higher modes beyond the fundamental level is essential in accurately characterising the seismic response, especially for buildings where higher structural modes play a significant role. The results show that approximating the VS profile with simplified procedures, as proposed by the Italian Building Code of 2018 (equivalent VS, similar to average), leads to incorrect estimates of seismic action....
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