Dynamic Response Characteristic of Building Structure under Blasting Vibration of underneath Tunnel

The vibration induced by blasting excavation of the subway tunnel in complex urban environments may cause harmful effects on adjacent buildings. Investigating the dynamic response of adjacent buildings is a key issue to predict and control blasting hazards. In this paper, the blasting excavation of the subway tunnel right below a building was selected as a case study, and the blast vibrations in the field were monitored. The Hilbert–Huang Transform (HHT) model was used to extract and analyze the time-frequency characteristic parameters of blasting dynamic response signals. By substituting intrinsic mode functions (IMF) component frequency and instantaneous energy for main frequency and blasting total input energy, respectively, the characteristics of time-instantaneous frequency-instantaneous energy of buildings under blasting seismic load were analyzed, and the concept of effective duration of vibration was proposed.

Late Middle Kingdom Temple Bakery at South Abydos

Recent excavations have exposed the original bakery belonging to the mortuary temple of Senwosret III at South Abydos. Initially founded as a six-chambered building, the bakery was expanded in several phases to become a larger complex that housed a series of chambers dedicated primarily to large-volume hearth baking. Associated ceramics show that baking practices involved parallel use of rough-ware trays (aprt) and cylindrical bread molds (bDA). The bakery was linked by a walkway system with adjacent buildings also involved in the production and supply of offerings to the temple. One of the neighboring buildings appears to have been a companion brewery that was removed and replaced during a phase of alteration to the production area. The bakery and related structures are components of a larger shena or production zone that once extended nearly 300 meters along the edge of the Nile floodplain between the temple and town at the site of WAH-swt-¢akAwra-mAa-xrw-m-AbDw. Evidence from the bakery and neighboring structures shows that the layout of the shena was an extension of the urban plan of the town of Wah-Sut. Flanked by the main institutional buildings, the site was spatially organized around this multi-activity production zone which formed the site’s economic and industrial nucleus.

Critical distance between two irregular adjacent buildings in order to prevent collision during earthquake

The aim of this study is to evaluate the value of suitable distance due to prevent the impact between two irregular adjacent buildings when earthquake is caused to occur large lateral displacement and damage the elements of buildings. For this purpose, by using a mathematical program based on neural network, the number of stories, the period and height of investigated models, PGD, PGV and PGA of earthquake records are defined and the nonlinear lateral displacements of different structures are determined in order to use in the program. Thus, the results of displacements based on all inputs are listed and the minimum critical distance is approximately estimated based on especial regression. For instance, a 3-4 story model is numerically investigated by Tabas earthquake record, which is suggested to provide required gap size about 70 cm. In fact, each model has to observe a 35 cm gap. A newly developed program based on mathematical equations are applied for determining the lateral displacements of each story. A new mathematical formula is proposed by neural network, which shows the least distance between irregular adjacent buildings. For investigating the accuracy of formula, two different ways are performed and the results of analyses confirm suggested equation. For this challenge, a 2-4 story model is considered and three different critical distances are calculated to be 59, 62 and 75 cm which show the last gap size is able to provide safety gap size, determined by suggested formula.

Predicting the peak structural displacement preventing pounding of buildings during earthquakes

The aim of the present paper is to verify the effectiveness of the artificial neural network (ANN) in predicting the peak lateral displacement of multi-story building during earthquakes, based on the peak ground acceleration (PGA) and building parameters. For the purpose of the study, the lumped-mass multi-degree-of-freedom structural model and different earthquake records have been considered. Firstly, values of stories mass and stories stiffness have been selected and building vibration period has been automatically calculated. The ANN algorithm has been used to determine the limitation of the peak lateral displacement of the multi-story building with different properties (height of stories, number of stories, mass of stories, stiffness of stories and building vibration period) exposed to earthquakes with various PGA. Then, the investigation has been focused on critical distance between two adjacent buildings so as to prevent their pounding during earthquakes. The proposed ANN has logically predicted the limitation of the peak lateral displacement for the five-story building with different properties. The results of the study clearly indicate that the algorithm is also capable to properly predict the peak lateral dis-placements for two buildings so as to prevent their pounding under different earthquakes. Subsequently, calculation of critical distance can also be optimized to save the land and provide the safety space between two adjacent buildings prone to seismic excitations.