大海参崴自由经济区规划与图们江地区规划的衔接

本文简单介绍了大海参崴自由经济区规划和图们江地区规划的设想,分析了前者与远东开放的密切联系和两个规划衔接的必要性及可能性,详细阐述两个规划衔接的具体领域,并预测了两个规划实施的必然趋势。     

ANALYTICAL MODELLING OF THE SEISMIC BEHAVIOUR OF PRECAST CONCRETE FRAMES DESIGNED WITH DUCTILE CONNECTIONS

Pure precast beam-column systems incorporate unbonded reinforced at the critical sections, causing strain incompatibility between steel and concrete. As a result, classical section analysis method, well know for characterising monolithic concrete members, cannot be directly applicable to these systems. This paper provides a section analysis method suitable for precast members, incorporating, through an analogy with equivalent cast-in-place solution named “monolithic beam analogy”, an additional condition on the member global displacement. The proposed method was first validated with the experimental data from tests on beam-column Hybrid subassemblages. Using appropriate hysteresis rules and the response envelopes defined by the section analysis method, a prediction of the behaviour of the PRESSS test building was carried out. Satisfactory agreements obtained between the analytical and experimental results confirm the validity of the suggested methodology. Derivation of the method and experimental validation are herein presented.     

Direct Displacement-Based Design of Glulam Timber Frame Buildings

We introduce a direct Displacement-Based Design methodology for glued laminated timber portal frames with moment-resisting doweled joints. We propose practical expressions to estimate ultimate target displacement and equivalent viscous damping, and we demonstrate that these expressions provide prior values that are close to those obtained a posteriori using a more refined model. Applied to case studies, the method yields base-shear forces lower than those obtained using the force-based approach of Eurocode 8. This is due to the high dissipation capacity of the specific connection technology, which apparently is conservatively accounted for in the q-factor of Eurocode 8.     

北京延庆岔道城明代城墙灰浆失效因素研究

古代砖砌墙体多用灰浆作为黏结材料,其老化失效是墙体损毁的重要原因之一.本文应用红外热成像仪、X-射线荧光分析仪、X-射线衍射仪和离子色谱仪等,分析了北京市延庆地区明代岔道城遗址灰浆及其保存环境状况,通过模拟老化试验探讨了影响其长期保存的主要因素,为此类砖砌墙体保护与维修提供依据.     

《中日和平友好条约》的签订

《中日和平友好条约》的签订经历了曲折的过程。中日双方于1974年11月开始缔约的预备谈判,后因日本政局变动使国内政治力量重组,自民党亲台势力掌控党政大权,在反霸问题上态度变化,导致谈判受阻;与此同时,中国也因文化大革命在缔约问题上回旋余地有限,致使缔约谈判一度中断。20世纪70年代末,日本国内政治环境和国际形势的变化为恢复中日谈判创造了有利条件,在邓小平的推动下,中日于1978年5月恢复了谈判,并于8月正式签署了《中日和平友好条约》,条约的签署对中日来说都具有重大意义。     

国际法视角下的1972年《中日联合声明》

1972年的《中日联合声明》掀开了两国关系新的一页。然而,时至今日,国内学界对这份文件的研究仍停留在表面。本文从国际法的角度,探讨了这份《声明》的法律性质,并且分析了《声明》中关于“战争状态结束”的条款,以及台湾条款和赔偿条款。本文最后得出结论：台湾问题是影响中日邦交正常化谈判的关键因素,日本通过很多外交手段为其对台政策留下了回旋的余地。     

Experimental Investigation of Exterior Unreinforced Beam-Column Joints with Plain and Deformed Bars

Experimental tests on four full-scale exterior unreinforced reinforced concrete (RC) beam-column joints, representative of the existing non-conforming RC frame buildings, are carried out. The specimens have different longitudinal reinforcements (plain or deformed) and they are designed in order to be representative of two typical design practices (for gravity loads only or according to an obsolete seismic code). Different failure modes are observed, namely joint failure with or without beam yielding. The local response of the joint panel is analyzed. The different joint deformation mechanisms and their contribution to the deformability and to the energy dissipation capacity of the sub-assemblages are evaluated.     

MODELLING OF RC BEAM-COLUMN JOINTS AND STRUCTURAL WALLS

The deformation of beam-column joints may contribute significantly to drift of reinforced concrete (RC) frames. In addition, failure may occur in the joints due to cumulative concrete crushing from applied beam and column moments, bond slip of embedded bars or shear failure as in the case of existing frames with nonductile detailing. When subjected to earthquake loading, failure in RC structural wall is similar to failure of frame joints as it may occur due to cumulative crushing from high flexural stresses, bond slip failure of lap splice, shear failure or a combination of various mechanisms of failure. It is important to include these behavioural characteristics in a simple model that can be used in the analysis of RC frames and RC walls to predict their response under earthquake loading and determine their failure modes.

Global macro models for the beam-column joint and for RC structural walls are developed. The proposed models represent shear and bond slip deformations as well as flexural deformations in the plastic hinge regions. The models are capable of idealising the potential failure mechanism due to crushing of concrete, bond slip or shear with allowance for the simultaneous progress in each mode. The model predictions are compared with available experimental data and good correlation is observed between analytical results and the test measurements.     

SEISMIC REHABILITATION OF BEAM-COLUMN JOINTS USING FRP LAMINATES

An innovative and practical technique for the seismic rehabilitation of beam-column joints using fiber reinforced polymers (FRP) is presented. The procedure is to upgrade the shear capacity of the joint and thus allow the ductile ftexural hinge to form in the beam. An experimental study is conducted in order to evaluate the performance of a full-scale reinforced concrete external beam-column joint from a moment resisting frame designed to earlier code then repaired using the proposed technique. The beam-column joint is tested under cyclic loading applied at the free end of the beam and axial column load. The suggested repair procedure was applied to the tested specimen. The composite laminate system proved to be effective in upgrading the shear capacity of the nonductile beam-column joint. Comparison between the behaviour of the specimen before and after the repair is presented. A design methodology for fibre jacketing to upgrade the shear capacity of existing beam-column joints in reinforced concrete moment resisting frames is proposed.     

Seismic Behavior of Reinforced Concrete Interior Wide-Beam Column Joints

In this article, experimental and finite element (FE) numerical investigations on interior wide-beam column joints are presented. The experimental research consisting of three full-scale interior wide-beam column specimens was carried out at Nanyang Technological University, Singapore to study the seismic behavior. Details of the test results are discussed to understand the specimens' seismic performance in terms of general behavior, hysteresis loops response, and strain profiles of longitudinal reinforcement. In the FE numerical study, the three-dimensional (3D) model developed is validated by comparing the analysis results with the experimental test results, which has shown a good agreement. A parametric study is performed to elucidate more information and to understand the influence of critical parameters affecting the joint behavior such as column axial load, beam anchorage ratio, and wide beam participation.