Abstract
The design mechanisms and methods of the invention are intended to minimize problems related to the safety of structures in the event of natural phenomena such as earthquakes, tornadoes, and strong winds. It is achieved by controlling the deformations of the structure. Damage and deformation are closely related concepts since the control of deformations also controls the damage. The design method of applying artificial compression to the ends of all longitudinal reinforced concrete walls and, at the same time, connecting the ends of the walls to the ground using ground anchors placed at the depths of the boreholes, transfers the inertial stresses of the structure in the ground, which acts as an external force in the structure's response to seismic displacements. The wall with the artificial compression acquires dynamic, larger active cross-section and high axial and torsional stiffness, preventing all failures caused by inelastic deformation. By connecting the ends of all walls to the ground, we control the eigenfrequency of the structure and the ground during each seismic loading cycle, preventing inelastic displacements. At the same time, we ensure the strong bearing capacity of the foundation soil and the structure By designing the walls correctly and placing them in proper locations, we prevent the torsional flexural buckling that occurs in asymmetrical structures, asymmetrical floor plans, and metal and tall structures. Compression of the wall sections at the ends and their anchoring to the ground mitigates the transfer of deformations to the connection nodes, strengthens the wall section in terms of base shear force and shear stress of the sections, increases the strength of the cross-sections to the tensile at the ends of the walls by introducing counteracting compressive forces. The use of tendons within the ducts prevents longitudinal shear in the overlay concrete, while anchoring the walls to the foundation not only dissipates inertial forces to the ground but also prevents rotation of the walls, thus maintaining the structural integrity of the beams. The prestressing at the bilateral ends of the walls restores the structure to its original position even in inelastic displacements by closing the opening of the restored cracks.
Keywords
Ultimate, Control-System, Anti-Seismic, Earthquakes, Construction, method, design
1. Introduction.
My extensive research, spanning the disciplines of civil engineering, geological engineering and mechanical, represents an innovative and interdisciplinary approach to the critical issue of the response of structures to seismic displacements. . There has been a significant shift in thinking in the field of earthquake resistant structures. Instead of simply adding more mass and reinforcement, which paradoxically increases seismic loads and costs, new innovative solutions are coming to the fore which, on the one hand, exploit external forces derived from from the ground, to improve the dynamic response of structures, combining the prestressed ends of longitudinal reinforced concrete walls, which acquire fully active, rigid and dynamic cross-sections, without adding additional mass, which increases inertia and costs.
The bilateral clamped wall with the ground deflects the compressive and tensile forces into the ground, and allows the ground to participate in receiving of the tension, by enhancing the response of the structure to seismic displacements, preventing the generation of large moments at the nodes due to the fact that it stops the turning of the walls and increases the stiffness of their trunk thereby maintaining the vertical position of the walls during the rocking of the earthquake preventing the deformation of the beams, pre compacts the ground in all directions, transfers the loads of the structure deep into the soil where there are stronger areas, reduces foundation costs.
The incorporation of this seismic design technology, which is based on mechanisms for compressing the edges of the longitudinal walls and simultaneously anchoring them to the foundation soil, promises to significantly increase the load-bearing capacity of the structure under the influence of strong seismic excitation. The thorough analysis of preliminary simulation and mathematical investigation results, which methodically determines the deviations, the determination of the orthogonal axial forces and their tabulation, which determines the loads to be absorbed by the ground, the comparable seismic experiments under scale up on a seismic base and the geological experimental investigation of both the ground and the anchoring mechanism, underline the paramount importance of precision and methodological rigour in research and analysis.
The ability of the methodology to mitigate deformations, eliminate tensile forces and moments and increase the active cross-section of the walls, preventing shear failure of the concrete coating along the steel bars, developed at the concrete-steel interface due to the steel's superior tensile strength and the concrete's low shear strength, presents a highly encouraging method of designing cheap and durable earthquake-resistant structures. Furthermore, the problem in the mismatch between the super tensile strength of steel and the small shear strength of concrete which was solved by the design methodology I develop, highlights the often overlooked complexities of material behavior during seismic events. My sustained effort to address these complexities is intended to significantly shape the development of cost-effective and robust seismic building methodologies.
While the economic and scientific recognition challenges I face are undoubtedly formidable, my unwavering dedication to this pivotal research underscores its potential to revolutionize the field, ultimately promoting safer and cheaper urban environments against seismic hazards.
Finding the optimal balance between elasticity, ductility, dynamics and cost efficiency remains a constant challenge. While elastic columns and rigid walls each have their advantages and disadvantages, a possible solution by placing elongated walls with prestressed and ground-fixed ends emerges as a promising but underutilized approach. These elongated walls with embedded and prestressed ends offer the potential to enhance the seismic resilience of structures and soils in redirecting seismic forces both by deflecting
the stress into the ground and by the active participation of the ground in the response of the structure to seismic displacements, increasing the load-bearing capacity of the structure. We now control the structure soil coordination since we have the possibility, through the dynamic participation of the soil, to mitigate the displacement in each seismic loading cycle. With dynamic ground participation and stiff walls we control the rocking of the structure so that it shifts within the elastic displacement range, eliminating inelastic displacements regardless of the acceleration magnitude and duration of the seismic event. The foundation soil enhance with the use of anchors because it is compacted in every direction before the construction of the building and the soil samples collected from the drilling of boreholes reveal the quality of the foundation soil before the construction is erected. This innovative concept promises not only to enhance structural performance but also to address cost concerns by substantially reducing the need for reinforcing materials, potentially revolutionizing seismic design practices in the construction industry. Furthermore, the method when applied to prefabricated houses made of reinforced concrete which have longitudinal double-lever walls, ( height and width ) increase the design efficiency, increase the height of the floors, reducing the cost compared to conventional housing, since as industrialized production products are 30 to 50% cheaper.
The earthquake imposes on the structure a horizontal displacement and some vertical components, which contain an unknown number of frequencies, unknown acceleration level, factors that contribute to the elastic or inelastic deformation of the structures. If the deformation is small enough to keep all members of the structure within the elastic region, the energy generated is energy stored in the structure and then dissipated to return the structure to its original position. As long as the deformation resulting from the rocking of the structure in the earthquake keeps any part of any member within the elastic region, some of the energy will be converted to frictional heat, while the energy stored in the structure will be released at the end of the cycle in the opposite direction. This displacement region is called the elastic region, in which no failures are observed. If the seismic energy (measured by ground acceleration) is too great, it will produce excessively large displacements, causing a very high curvature in the vertical and horizontal elements. If the curvature is too high, it means that the rotation of the column and beam sections will be well above the elastic range (concrete compressive strain above 0.35% and reinforcement fibre stresses above 0.2%) beyond the yield strength. When the rotation goes beyond this elastic limit, the structure starts to dissipate energy storage through plastic displacement, which means that the sections will have a residual displacement that will not be able to be recovered.
The strength design of a current building is limited to the limits of the elastic design range, and then it passes to inelastic displacements, exhibiting leakage and plastic deformations. If the load-bearing elements of the structure experiencing plastic deformations exceed the breaking point limit, and there are too many of them on the structure, the structure will collapse. By the design method of connecting the ends of the top level of the longitudinal walls to the ground and by imposing artificial compression on their cross sections, I hope to stop their rotation, deflect the lateral inertia stresses into the ground, and increase the stiffness of the structure, stopping the inelastic deformation that causes earthquake failures
In an earthquake, the columns lose their eccentricity and their bases are lifted, creating torques at all the nodes of the structure. There is a limit to the eccentricity of the base of which part of one edge is lifted by the rollover moment. To minimize the twisting of the bases, we place strong foot girders in the columns. In the large longitudinal walls, due to the large moments which occur during an earthquake, it is practically impossible to prevent rotation with the classical way of construction of the foot girders.
If we want stronger structures we must prevent the causes of failure and the causes of inelastic deformation in general. The overturning moment of the structure and walls, base shear, shear failure, inadequate bearing capacity of the foundation soil, and shear failure of the concrete overlay that develops along the bars over the concrete and steel interface due to the over tensile strength of the steel and the low shear capacity of the concrete, are some of the destructive factors of structures that deserve more research. The inevitable inelastic behaviour of structures needs to be controlled. The wall sections must be made stronger, capable of absorbing all the forces. The overturning moment of the structure and the walls must be prevented so that it does not create the fishy moments around the nodes. We need to increase the bearing capacity of the soil We need to eliminate the tension at the wall faces that cause the shear failure in the overlay concrete.
We need to increase the stiffness of the vertical elements of concrete, we need to stop the increasing deformation from the duration and ground construction coordination But the main thing to do is to divert the inertia of the structure into the ground.
Compression of the walls by means of the prestressing mechanism increases the active cross-section, corrects the arrows of the oblique tensile, increases the capacity towards base shear and shear failure of the cross-sections, increases the bearing capacity of the structure, reduces deformation by increasing the stiffness of the wall frames, reduces or even eliminates tensile stress at the ends, reduces deformation and preventing the generation of large moments at the nodes.