高层建筑基础不均匀沉降对结构危害的探讨

随着建筑行业的快速发展,高层建筑越来越多,在基础设计方面出现了很多问题,例如通常会在工程中见到结构基础有不均匀沉降的现象发生,这对高层建筑来说是一个非常重要的问题。本文主要针对高层建筑基础不均匀沉降的预防加以介绍。

二化螟危害结构及产量损失初探

通过对水稻二化螟在自然发生条件下的危害结构、水稻被害节位与产量损失的考查，表明在吉林稻区二化螟的危害结构有死孕穗、白穗和虫伤株，其中主要是虫伤株，占９２８０％。二化螟的蛀茎节位８２４４％集中在穗下３、４节上，并随着被害节位的增多和愈向上位节，瘪粒率愈高，产量损失愈大。

道路桥梁常见结构性危害及其加固技术分析

简要介绍我们国家道路桥梁实际现状的基础上,对其中出现的显著影响道路桥梁使用的结构性危害进行了描述,并指出其出现的原因,在此基础上,还进一步的提出了对出现了结构性危害的道路桥梁进行加固的必要性和实际的施工方法,既有理论上的论述,也同时兼顾工程实践的需求。

浅析房屋建筑工程结构裂缝控制及处理技术

随着我国建筑行业和房地产行业的飞速发展,大量的房屋建筑工程项目应运而生,而开发商在尽可能的满足人民使用需求的同时也在最大化的追求经济效益,他们一位的追求工期进度,并不够重视房屋建筑项目的建设质量,这就导致了房屋建筑在建设过程中经常会出现质量问题,其中裂缝问题就是一类常见问题,如果没有及时有效的处理好裂缝问题,那么不但会大大的影响建筑的安全性,甚至还会导致房屋建筑无法顺利竣工交付。从我国房屋建筑工程结构裂缝的主要危害、房屋建筑工程结构裂缝的形成原因和房屋建筑工程结构裂缝的控制处理技术三方面详细的讨论了如何有效的控制和处理房屋建筑工程的结构裂缝问题。

The Morphology, Phase Composition and Effect of Corrosion Product on Simulated Archaeological Iron

The immersion corrosion of archaeological iron in solution(0.06mol·L- 1NaCl+0.03mol·L -1 Na2SO4+ 0.01mol·L- 1 NaHCO3)simulating soil water composition was presented.The evolution of archaeological iron from iron to iron oxide and to iron oxy-hydroxides compounds was investigated by scanning electron microscope(SEM) and X-ray diffraction(XRD)analysis.According to the morphology,phase composition,and transformation proc- ess,the contributions of each corrosion product to archaeological iron were discussed.

System failure analysis based on DEMATEL–ISM and FMECA

A new method of system failure analysis was proposed. First, considering the relationships between the failure subsystems,the decision making trial and evaluation laboratory(DEMATEL) method was used to calculate the degree of correlation between the failure subsystems, analyze the combined effect of related failures, and obtain the degree of correlation by using the directed graph and matrix operations. Then, the interpretative structural modeling(ISM) method was combined to intuitively show the logical relationship of many failure subsystems and their influences on each other by using multilevel hierarchical structure model and obtaining the critical subsystems. Finally, failure mode effects and criticality analysis(FMECA) was used to perform a qualitative hazard analysis of critical subsystems, determine the critical failure mode, and clarify the direction of reliability improvement.Through an example, the result demonstrates that the proposed method can be efficiently applied to system failure analysis problems.

Hazard degree identification of goafs based on scale effect of structure by RS-TOPSIS method

In order to precisely predict the hazard degree of goaf(HDG), the RS-TOPSIS model was built based on the results of expert investigation. To evaluate the HDG in the underground mine, five structure size factors, i.e. goaf span, exposed area, goaf height, goaf depth, and pillar width, were selected as the evaluation indexes. And based on rough dependability in rough set(RS)theory, the weights of evaluation indexes were identified by calculating rough dependability between evaluation indexes and evaluation results. Fourty goafs in some mines of western China, whose indexes parameters were measured by cavity monitoring system(CMS), were taken as evaluation objects. In addition, the characteristic parameters of five grades' typical goafs were built according to the interval limits value of single index evaluation. Then, using the technique for order preference by similarity to ideal solution(TOPSIS), five-category classification of HDG was realized based on closeness degree, and the HDG was also identified.Results show that the five-category identification of mine goafs could be realized by RS-TOPSIS method, based on the structure-scale-effect. The classification results are consistent with those of numerical simulation based on stress and displacement,while the coincidence rate is up to 92.5%. Furthermore, the results are more conservative to safety evaluation than numerical simulation, thus demonstrating that the proposed method is more easier, reasonable and more definite for HDG identification.

Investigation of Combination Characteristic of Damage Location and Intensity in Arch Using Wavelet Coefficient

Arch is a typical complex structure comparing with beam and plate in bridge system. This paper investigates the damage characteristic combining the crack location with the crack intensity in arch. Initially, the first four displacement modes of intact and different damaged arch are simulated and the displacement mode changes are obtained. Next, the wavelet transformation is applied to the displacement mode changes in arch and wavelet coefficients at damage loci are picked. Finally, the damage index including damage location and damage intensity in arch is provided and plotted. The results show that wavelet coefficient module maximum of mode changes can be the damage indicator and is influenced by damage location and damage intensity. The damage indicator is proportional to the damage intensity and present monotonic trend according to damage location which depend on the mode order. At the same time, the large modulus maximum corresponds to small damage combination of location and intensity in the first four modes.

浅析混凝土裂缝的探讨

针对钢筋砼结构在设计、材料选择、砼自力收缩及施工过程各个环节产生裂缝的因素，分析并相应提出了一些切实可行的防控措施及有关裂缝的处理方法。

工民建施工中不良地基土的改造技术分析

近几年,我国国民经济得到迅猛发展,促使城市建设产生了更加多的需求,加上现代化建设要求的多元化,这样就要求建筑施工过程中要保障整体结构的安全性稳定性。目前在建筑施工中地基的良好性直接影响着建筑整体结构的质量。在地基中不乏存在着不良地基土,没有进行及时的改造和加固的话,将严重影响整体后续工作的进行,同时也会带来一定的安全事故。改良地基土的工序一般要遵循科学、合理以及具有一定成效的原则,通过相应的技术改良整体提升地基土的参透性、承受力以及变形特性等。本文通过对工民建施工中不良地基土的危害、主要表现形式进行简要分析,从而提出相应的技术改良措施,保障整体地基土高质量,降低施工工艺流程以及施工项目成本费用。