PEG加固处理木质遗存变色的原因探析

采用不同的PEG加固处理方法,通过宏观、微观分析、Lab值检测等,探析不同PEG加固方法与木质遗存变色之间的相关关系,对研究木质遗存的腐朽程度和机制具有重要的参考意义。结果表明：缓冲溶液对加固后木质遗存材色加深有抑制作用,草酸盐缓冲溶液浸泡的试样材色最接近木材本色;用草酸盐溶液处理加固木质遗存的效果优于EDTA-2Na和PVP溶液,其试样更易制作木材切片。     

海门口遗址饱水古木酚醛树脂加固机理分析

在酚醛树脂加固古木效果评价的基础上,采用扫描电子显微镜和荧光显微镜对微观构造进行解析,结合X射线衍射和傅里叶变换红外光谱对酚醛树脂加固古木的加固机理进行分析。结果表明：浸入古木内的酚醛树脂绝大部分沉积在了细胞壁内,极少量以块状形式沉积在了细胞腔内;加固后古木自身纤维素结晶度有所提高;虽然侵入的酚醛树脂发生了一定程度的固化,但仍未形成大量的三维体型丙阶酚醛树脂。     

不同竹龄毛竹增强相的动态热机械研究

利用动态热机械分析仪检测不同竹龄的毛竹,实验证明:在常温条件下,毛竹竹青的刚性随毛竹竹龄的增加而增加,当毛竹到了一定竹龄后,其竹青的刚性渐渐趋于稳定。一般5~6年生的成熟毛竹的竹青部分的常温存储模量位于10¹⁰Pa(10GPa)数量级以上,一般能满足做为风力发电叶片复合材料中增强相材料的使用。因此,最佳的风力发电叶片复合材料增强相材料是5~6年生的成熟毛竹。     

Reinforcement Treatment on the Uneven Subsidence of Foundation

There are several methods to cope with the common problem of the uneven subsidence of foundation. The reason for uneven settlement of foundation of the frame structure was analyzed in this paper. Considering the limitation of the construction site and the principle of consolidation, a feasible reinforcement measure was taken. Meanwhile, a practical construction pattern was chosen upon the comparison of the reinforcement technology analysis and the construction method. The observation of the settlement result after consolidation of the structure shows that the result of this reinforcement treatment pattern is effective.     

粘钢加固技术的设计与应用

粘钢即在被加固构件表面粘贴钢板，籍以提高其承载能力，目前粘钢技术已在实际工程中得到广泛应用，技术日趋成熟，粘钢有施工简便、工期短、占用的空间小等优点；本文根据施工经验提出施工方法，以利在实际加固当中取得较好的经济效益。     

地下防水工程渗漏水的修堵

作者结合实践,分析了地下工程渗漏水的原因往往是由于设计不合理及施工不规范而造成的,并提出了相应的防治措施。     

不同乔木根系的抗拉力学特性

为了揭示植被根系的固土力学机制,筛选合适的水土保持树种,选取华北地区5种常见乔木油松、蒙古栎、白桦、落叶松和榆树根系进行室内单根拉伸试验。结果表明,5种乔木根系极限抗拉力和直径之间存在显著的幂函数关系;油松和白桦根系抗拉强度随着直径增大以幂函数递减,蒙古栎、落叶松和榆树根系的抗拉强度随直径增大均以对数函数递减。拉伸过程中,根系对外界拉力的敏感性是在一定范围内的波动,5种乔木平均敏感性依次为白桦＞落叶松＞榆树＞油松＞蒙古栎。5种乔木根系不同直径的应力应变曲线特征参数不同,但均为单峰曲线,具有弹塑性材料特征,拟合曲线三阶抛物线模型能很好地反映其基本特征。不同树种不同直径的抗拉力学特征存在很大的差别,其内在原因还需要进一步的研究。     

Root tensile strength of three shrub species: Rosa canina, Cotoneaster dammeri and Juniperus horizontalis: Soil reinforcement estimation by laboratory tests

The presence of vegetation increases soil burden stability along slopes and therefore reduces soil erosion. The contribution of the vegetation is due to mechanical (reinforcing soil shear resistance) and hydrologic controls on stream banks and superficial landslides. This study focused on the biotechnical characteristics of the root system of three shrub species: Rosa canina (L.), Cotoneaster dammeri (C.K. Schneid) and Juniperus horizontalis (Moench). The aim of this paper is to increase our understanding on root biomechanical properties of shrubs species and their contribution to soil reinforcement. The considered shrubs grew up in wood containers, exposed to natural conditions in a village near Asti (Northern Italy) for 2 years. Laboratory tests were conducted to measure the ultimate root tensile strength and to estimate the root density distribution with depth (root area ratio), in order to quantify the soil mechanical reinforcement. Root tensile strength measurements were carried out on single root specimens and root area ratio was estimated analyzing the whole root system. The improvement of soil mechanical properties obtained by the presence of shrubs was estimated using two different models. The first model, based on a simple force equilibrium model, considers that the tensile strength of all roots crossing the shear plane is fully mobilized. This classical approach is implemented by the Fiber Bundle Model concept, to account for non-simultaneous root breaking. C. dammeri roots presented the highest tensile strength and soil reinforcement values, while R. canina and J. horizontalis were characterized by lower values. Similarly at each considered depth C. dammeri showed the highest soil reinforcement effect.     

浅谈牡丹江市天长山水库除险加固的必要性

目前,我国许多水库仍存在着施工技术落后、防洪标准偏低,而且达不到相关规范要求,工程老化等情况;这样就形成了大量的病险水库,其危害严重地威胁着下游人民的生命及财产安全。因此笔者就牡丹江市天长山水库病险的基本情况,阐明了除险加固的必要性。     

Cause Analysis and Treatment Measure on Cracks in New Reinforced Concrete Restricted by Old Web Concrete

In this paper, the cause analysis about cracks on the new concrete web poured in multi -span continuous box -girder of a main bridge was introduced. This bridge is a prestressed concrete one with variable cross sections and an 80 -meter main span. When casting reinforced concrete in large volume in box girder during vehicle transport service, the shrinkage cracks in cast -in place reinforced web concrete were formed due to the restriction of old web concrete. Then, the control measure taken on these cracks is discussed.