Analysis of Deformation Characteristics of Reverse Slope Under The Influence of Reservoir Water Based On Community Detection

In order to study the deformation characteristics of reverse slope, this paper took the slope of Xiaodongcao as the research object, applied the Louvain community detection algorithm, considered the influence of reservoir water level change, partitioned the slope deformation characteristics. The deformation characteristic zoning result was superimposed with the slope displacement cloud map and three types of geological geometric characteristic factor zoning map obtained by ArcGIS. The results show that：Community detection can quickly identify the closely connected part of slope network, and the specific location of this part is affected by reservoir water. After the community detection result is superimposed with the displacement cloud map, the areas with large deformation and close connection in the slope can be identified. It is found that the community with severe deformation have at least 5% more displacement and up to 21% more displacement than that with slow deformation. In addition, the location of leader nodes can be identified, and the number of leader nodes does not exceed 20% of the total nodes in the community, and its average displacement is at least 10% more than that of ordinary nodes, up to 36%. After the community detection result is superimposed with the zoning map of slope grade, it can be concluded that the slope grade within the community with severe deformation is greater than 60°, indicating that the larger slope grade is more sensitive to the bank slope deformation.

Microstructure and Mechanical Properties of Spark Plasma Sintered and Severely Deformed AA7075 Alloy

In this paper, the microstructure and mechanical properties of AA7075 with a coarse-fine-grained laminated microstructure produced by spark plasma sintering (SPS) and the cyclic extrusion severe deformation (KOBO) technique were investigated. It was found that an inhomogeneous grain microstructure was formed from coarse and fine grains by the SPS process and then was transformed into a coarse-fine-grained laminated microstructure by means of KOBO extrusion at room temperature. The grain refinement during KOBO extrusion resulted in a fine grained laminated microstructure created due to the formation of low-angle grain boundaries (LAGBs), followed by dynamic recrystallization, leading to high-angle grain boundaries (HAGBs). The EBSD analysis results reveal the formation of a deformed and partially recrystallized ultrafine grain microstructure owing to the generation and development of shear bands during KOBO extrusion. The ultimate tensile strength (UTS) of the AA7075 alloy rose after SPS-KOBO severe deformation up to 422 MPa, with high strains of about 33%. The obtained results clearly show that the SPS-KOBO extrusion technique allows a bimodal laminated fine gradient grain microstructure to be obtained due to deformation and dynamic recrystallization, which result in both high strength and good ductility. The new heterogeneous AA7075 alloys obtained by the SPS-KOBO combined techniques demonstrate that microstructural heterogeneities can assist in overcoming the strength–ductility trade-off.

REHABILITATION OF BRICK-WALL FAÇADES

This abstract seeks to analyze several existing cracking rehabilitation techniques on brick-wall façades. The examples concern to an upper-middle class housing complex, situated in Porto, Portugal. This housing complex holds 4 buildings (190 dwellings) and which construction is near 20 years old. The most significant anomalies that have been checked on this rehabilitation study were the cracks of the lintels over windows and on wall-corners of balconies. Both represent a severe anomaly on brick-wall façades that will have as consequence rain penetration and water infiltration. As result, one found that the horizontal lintel cracks occur as a consequence of conception mistakes due to a reduced armor support and to a poor covering. The lintel deformation will allow rain penetration through walls and water infiltrations into dwellings and provoke the severe deformation of the windows’ frames and, hereafter, problems with its opening. Beyond this the vertical wall-corner cracks are a consequence of a wrong procedure performed with the cut of the bricks. Regarding the horizontal lintel cracks, the method for its rehabilitation involves the demolition of the brick-wall façade and the execution of angle brackets before rebuilding the brick-wall. In respect to the vertical wall-corner cracks, the method for the rehabilitation consists on the stapling, using the application of stainless-steel helical pins to provide a strong mechanical solution when patch repairing the brick-wall (patch pin).