This paper presents a study on excavation-induced deformation characteristics of ground and adjacent building using three-dimensional (3D) decoupled simulations. A decoupled analytical technique is proposed to enhance...
详细信息
This paper presents a study on excavation-induced deformation characteristics of ground and adjacent building using three-dimensional (3D) decoupled simulations. A decoupled analytical technique is proposed to enhance the consideration of both the 3D nonlinear soil behavior and the inelastic structure responses. The excavation effects and the adjacent structure's responses are decoupled and simulated by two separate programs: PLAXIS 3D for excavation and SAP 2000 for structure. Two models are bridged by a simple iteration scheme. A well-documented excavation case history and low-rise framed building are used for demonstration. The obtained results exhibit that the decoupled analytical method is feasible to incorporate properly the 3D nonlinear soil behavior and the inelastic structure responses. It also seems practical to use since the numerical outcomes often converge within several iterations. The analytical results show that the lateral and vertical movements of the structure are significantly different from those of the greenfield ground. In addition, more in-depth inelastic structure responses can be investigated such as where the plastic hinge may occur in the structure. This is a significant advancement as it provides additional insights on assessing the building's potential damage and serviceability.
Large scale earthquakes occur frequently in Japan in recent years. In the Great East Japan Earthquake that occurred in 2011 and caused major damage, more than 90% of the dead were due to the tsunami. The speed of evac...
Large scale earthquakes occur frequently in Japan in recent years. In the Great East Japan Earthquake that occurred in 2011 and caused major damage, more than 90% of the dead were due to the tsunami. The speed of evacuation is important in considering evacuation at the time of the attack of the tsunami, especially the elderly evacuation speed is assumed to be slower than non-elderly people. Elderly people may have different means of evacuation and speed depending on the composition of the households to which they belong because of the different possibilities of riding in families’ driven cars. However, a simulation taking such a difference of evacuation into consideration has not been conducted. The purpose of this study is to conduct a tsunami evacuation simulation in consideration of evacuation measures and speed depending on the type of households belonging to in the tsunami inundation area of Toyohashi city, Japan. In order to conduct the tsunami evacuation simulation considering the household type, detailed data on individual households is necessary. However, it is difficult to obtain from aggregated data such as National Census. Therefore, detailed data on individual households is created by using the household micro data estimation system developed by Sugiki et al. [1]. Evacuation simulation is performed by shortest path search using Esri’s ArcGIS Network Analyst’s OD cost matrix analysis. The elderly people who cannot complete evacuation by the time of the arrival of the tsunami were found from evacuation simulation results assuming evacuation measures available for each household attribute to which the evacuees belong.
Although mainstream of multinational construction firms have origin from developed countries, the relevance of construction contracting firms (CCFs) from developing countries is on the rise and becoming increasingly i...
详细信息
Purpose - The purpose of this paper is to examine the implementation of quality management systems (QMSs) of Grade 7 (G-7) Indonesian construction companies. This includes the initial motives that have driven the deve...
详细信息
作者：
Irena GołębiowskaMaciej DutkiewiczFaculty of Civil
Architecture and Environmental Engineering Department of Building Construction University of Science and Technology in Bydgoszcz Al. Prof. S. Kaliskiego 7 85-796 Bydgoszcz Poland
Paper concerns the wind flow around the bridge cable for Reynolds number Re=1,4x105. The purpose of the paper is to describe aerodynamic force coefficients of drag and lift and their frequencies, distribution of veloc...
Paper concerns the wind flow around the bridge cable for Reynolds number Re=1,4x105. The purpose of the paper is to describe aerodynamic force coefficients of drag and lift and their frequencies, distribution of velocity of flow near the two-dimensional circle and ellipse cylinders that can model the bridge cables. In the analysed case, the RNG k – ɛ method belonging to the Reynolds-Averaged Navier-Stokes models was used. The numerical simulations are performed for different aspect ratio, as the shape of cross section of bridges' cable is significant. The ellipse section models the shape with ice on the cable. Especially ice and water drops on cables make the unstable of response that cause the fatigue stresses and faster failure of the cables.
作者：
Yoo, WankyuKim, Byoung-IlCho, Wanjei1.SOC Research Institute
Geotechnical Engineering Research Division Korea Institute of Construction Technology Ilsan 411-712 Korea 2.Dept. of Civil and Environmental Engineering Myongji University Yongin 449-728 Korea 3.Dept. of Civil and Environmental Engineering Dankook University Yongin 448-701 Korea
When constructing structures receiving high vertical and horizontal force such as port facilities, caissons and breakwaters on a soft ground on the sea or seashore, it is very important to increase the strength of the...
详细信息
When constructing structures receiving high vertical and horizontal force such as port facilities, caissons and breakwaters on a soft ground on the sea or seashore, it is very important to increase the strength of the ground and inhibit excessive settlement. Recently, there have been numerous studies on the method of wrapping the outer wall of granular piles with geotextile or geogrid that has a certain level of tensile strength. Since the geotextile increases the strength of granular piles by confinement effects, those confined granular piles more advantages than the Conventional Sand Compaction Piles (SCP) in terms of the bearing capacity and settlement. Furthermore, this method consumes less aggregate compared to the conventional Sand Compaction Pile (SCP) or Gravel Compaction Pile (GCP) method. This study proposed to determine the characteristics of mechanical behaviors such as bearing capacity and stress concentration ratio of a composite ground improved using SCPs reinforced with geotextile (Geotextile-Encased Sand Pile, GESP) as an alternative to the conventional SCP method. With this purpose, several loading tests were conducted on the artificially sedimented clay grounds reinforced using conventional SCPs and GESPs with geotextiles of three different tensile strengths with various replacement ratios. Based on the results of this study, the bearing capacity of the soft clay ground reinforced by the GESPs is larger than that of the soft ground reinforced by the conventional SCPs and the failure mode of the GESPs is buckling different from the bulging of the SCPs. The tensile strength of the geotextile has little effect on the bearing capacity in the buckling failure of GESPs.
The Compaction grouting (CPG) method is one of the liquefaction countermeasures to increase the density of improved ground by injecting mortar statically into the ground. CPG is often adopted just below or near the ex...
详细信息
作者：
Irena GołębiowskaMaciej DutkiewiczFaculty of Civil
Architecture and Environmental Engineering Department of Building Construction University of Science and Technology in Bydgoszcz Al. Prof. S. Kaliskiego 7 85-796 Bydgoszcz Poland
The subcritical flow regime of Reynolds number Re = 1.0 x 104 is the subject of the paper in the context of aerodynamic interference of tandem circle cylinders. The two cylinders are in distance of L/D equal to 2.0. T...
The subcritical flow regime of Reynolds number Re = 1.0 x 104 is the subject of the paper in the context of aerodynamic interference of tandem circle cylinders. The two cylinders are in distance of L/D equal to 2.0. The purpose of the paper is to determine aerodynamic drag and lift coefficients and the frequencies for upstream and downstream cylinders and also the distribution of the velocity around the cylinders and in their wakes. In numerical analysis the RNG k – method was used.
In the field of identifying cast-in-situ pile defect types, a new method, i.e., optimized energy method (OEM) is proposed to overcome the low accuracy and reliability of traditional method. In OEM, wavelet transform (...
详细信息
Fragility curves for typical multi-span simply supported concrete box girder bridges in eastern China are presented. A set of bridge samples, in which five uncertain parameters are considered, are established using th...
详细信息
Fragility curves for typical multi-span simply supported concrete box girder bridges in eastern China are presented. A set of bridge samples, in which five uncertain parameters are considered, are established using the Latin hypercube sampling. Nonlinear time history analyses are conducted to capture the structural response quantities. Probabilistic seismic demand models are formulated by quadratic regression analysis for the capacity/demand ratios. Fragility curves of bridge components are developed and the fragility of bridge system is evaluated using the firstorder bound method. The results show that the columns and expansion bearings among bridge members are more fragile under earthquake excitation, and the bridge system is more fragile than any bridge component. The typical bridges have more than 50% probability when subjected to PGAs of 0.46, 0.58, 0.82, and1.0g for four damage states, respectively. The fragility curves can be used for retrofit prioritization for this type of bridges.
暂无评论