寒区水库土石坝护坡防冰冻破坏技术及应用

寒冷地区水库土石坝护坡, 冬季受冰冻作用, 普遍发生严重破坏. 这种破坏主要是由护坡基土残余冻土层冻胀、冰推力及冰层弯矩等共同作用造成的. 在分析破坏机理及过程的基础上提出削减和抵抗冰冻坡坏作用的结构型式和设计计算方法.     

Midbroken reinforced concrete shear frames due to earthquakes. A hysteretic model to quantify damage at the storey level

A nonlinear hysteretic model for the response and local damage analyses of reinforced concrete shear frames subject to earthquake excitation is proposed, and, the model is applied to analyse midbroken reinforced concrete (RC) structures due to earthquake loads. Each storey of the shear frame is represented by a Clough and Johnston hysteretic oscillator with degrading elastic fraction of the restoring force. The local damage is numerically quantified in the domain [0,1] using the maximum softening damage indicators which are defined in closed form based on the variation of the eigenfrequency of the local oscillators due to the local stiffness and strength deterioration. The proposed method of response and damage analyses is illustrated using a sample 5 storey shear frame with a weak third storey in stiffness and/or strength subject to sinusoidal and simulated earthquake excitations for which the horizontal component of the ground motion is modeled as a stationary Gaussian stochastic process with Kanai-Tajimi spectrum, multiplied by an envelope function.     

抗拔法测强曲线的建立与应用

本文应用先进的CAPO实验仪 ,建立了广州地区抗拔法测定结构混凝土强度的经验曲线 ,并取得了较好的应用效果     

钢筋混凝土薄壁结构爆破参数的确定

结合阜新发电厂冷却塔爆破拆除工程实践，研究了钢筋混凝土薄壁结构中破参数的选取问题，并了该工程中的防护措施。     

泡沫覆盖的随机粗糙海面的双站散射和热辐射

从双尺度随机粗糙面的散射理论和矢量辐射传输理论出发，将具有白帽泡沫覆盖的风驱海面模拟成一层离散球形粒子下垫双尺度随机粗糙界面的复合模型．利用Ｐｉｅｒｓｏｎ的半经验海洋波高谱和修正的Ｃｏｘ和Ｍｕｎｋ的坡度分布函数，推导了强风驱使下白帽泡沫覆盖的随机起伏海面的双站散射系数和热发射率，得到了极化的双站散射和热发射与海面各物理参数之间定量的函数关系．数值计算的结果与已有的海洋遥感实验数据进行了比较和讨论．     

基于响应面法的软岩隧道湿喷纤维混凝土支护结构可靠度分析

由于湿喷纤维混凝土支护结构物理、力学参数和喷层厚度的离散性及混凝土强度破坏准则难以用支护材料参数显式表达,对该类隧道支护结构进行可靠度分析十分困难,提出采用响应面方法计算湿喷纤维混凝土支护结构的可靠度方法,并给出了计算流程,其中围岩-支护结构的确定性分析采用非线性有限元方法,可靠度分析采用2次响应面法.以赣州-龙岩铁路金华山软岩隧道湿喷纤维混凝土支护结构为研究对象,对该支护结构的可靠度进行分析与计算.分析结果表明,金华山隧道湿喷纤维混凝土支护结构可靠度指标高,处于安全状态.     

水泥砼路面板的破坏原因及对策

针对合六叶公路水泥砼面板产生断板等病害,分析了水泥砼面板的破坏原因,并且根据面板破坏的不同情况提出维修方案。     

混凝土垫层对围护墙支撑效应的监测分析

控制基坑变形是保证基坑及周边环境安全的关键,而底板施工期间墙体变形的控制更是关注的重点。结合上海轨道交通某在建地铁车站基坑开挖时的变形监测数据及跟踪工况,对素混凝土垫层的支撑约束作用进行了监测分析。坑底暴露时间对底板施工阶段内的基坑变形有着显著影响,基坑暴露时间的长短是控制底板施工期间围护墙变形的关键。素混凝土垫层对围护墙体变形具有一定的支撑效应,在一定程度上能起到类似结构底板的作用。施工中应尽快完成混凝土垫层的浇筑工作,尽早发挥垫层对围护墙体的支撑作用。垫层对墙体的支撑效果与其自身的平直度等因素有很大关系,破坏垫层的整体性,则会削弱其对围护墙体的支撑作用。提出对坑底施工阶段基坑变形的控制措施,缩短底板施工阶段的暴露时间,提高垫层的整体性,加快底板施工,尽早形成底板混凝土对围护墙体的支撑作用,从而控制开挖阶段的基坑变形,对其他深基坑工程具有一定的参考价值。     

Experimental Evaluation of Recycled Aggregate Porous Concrete Piles for Soft Ground Improvement

The use of sand compaction pile or gravel compaction pile is nowadays a common approach for soft ground improvement. In this article, a recycled aggregate porous concrete pile has been developed by replacing natural aggregates with recycled aggregates to overcome issues related to bulging failure or reduced section geometries. Such issues may arise during installation and during the early stages of operation. In addition, the proposed approach utilizes recycled aggregates instead of natural materials. To investigate the applicability of the recycled aggregate porous concrete pile method as a ground improvement technique, a series of laboratory model consolidation tests was performed on soft clay soil reinforced with sand compaction pile, gravel compaction pile, and recycled aggregate porous concrete pile, respectively. The results indicated that the settlement reduction effect of recycled aggregate porous concrete pile was significantly higher than the sand compaction pile and gravel compaction pile methods. The stress sharing ratio from the experimental program showed good agreement with those calculated by elasticity theory. Comparative analyses of the recycled aggregate porous concrete pile versus sand compaction pile and gravel compaction pile approaches, under the same replacement area ratio and surcharge pressure, showed significantly improved consolidation time, settlement reduction, and stress sharing effect.     

干法喷射混凝土技术在高边坡预应力锚索（杆）框架工程中的应用

混凝土质量是影响预应力锚索（杆）框架结构的关键因素,它直接影响着边坡加固的效果,高边坡框架现浇混凝土施工受现场条件限制,存在离析、振捣不到位、跑浆、胀模、劳动力成本偏高等问题,干法喷射混凝土可有效解决以上难题。本文结合甘肃小厂坝矿山环境恢复治理工程（二期）预应力锚杆框架施工的成功经验,对干法喷射混凝土施工的施工工艺及技术要点进行了介绍。