HBT－50型混凝土泵的研制          下载免费PDF全文

张明  胡汉月  朱菊根 《探矿工程》1996,(3):48-49

介绍了ＨＢＴ－５０型混凝土泵的设计特点,结构参数及使用情况。  相似文献   

Quality Assessment of Concrete Blocks Exposed in Nature for Eighty Years     

Hu Yuchu  Wu Shaozhang Lu Liyun Senior Engineer  Nanjing Hydraulic Research Institute  Nanjing Professor  Senior Engineer  Nanjing Hydraulic Research Institute  Nanjing Assistant Engineer  Nanjing Hydraulic Research Institute  Nanjing 《中国海洋工程》1992,(4)

The concrete blocks used on a jetty in Shanghai were made in 1909 and 1910. Having been exposed in nature for 80 years, now there are 4600 pieces of blocks left on the jetty. Comprehensive inspections, such as external appearance examination, core-drilling of concrete blocks, ultrasonic detection, nuclear densimeter inspection and in-door and out-door chemical analysis, show that 75% of the blocks are of the rebound number of 21 - 23, and the saturated limit compressive strength and dry limit compressive strength of 10MPa; the carbonized depth of concrete is 1 - 2 mm. Compared with the state of the jetty in 1968, already used for 60 years then, the jetty is expected to serve another 40 years or more after being repaired.  相似文献   

基于人工神经网络的混凝土疲劳寿命估算   总被引：9，自引：2，他引：9  

吕培印  宋玉普 《海洋工程》2001,19(3):72-76

把决定混凝土疲劳寿命的应力水平，应力比，加载频率和描述随机性的破坏概率作为神经网络的输入，以疲劳寿命作为网络的输出，用网络结构描述它们之间的非线性关系，利用实验数据样本完成了网络的训练，并对模拟样本进行了估算，实例计算了结果表明，利用已有疲劳试验数据训练好的人工神经网络进行混凝土疲劳寿命估算，可部分代替冗长，昂贵的疲劳实验。  相似文献   

混凝土强度快速试验(4h压蒸养护法)--连云港地区强度推定式的建立     

张海涛  潘勇  乔乃洪  杨世兵 《海岸工程》2003,22(4):7-15

为了快速推定混凝土强度，根据《公路工程水泥混凝土试验规程》(JTJ053-94)“混凝土强度快速试验(4h压蒸养护法)”，对不同塌落度、水灰比的混凝土进行试验。在大量试验的基础上，建立了连云港地区混凝土强度推定式。并对推定式的应用范围进行了分析，试验数据表明所建立的推定式能够应用于当地公路工程建设。  相似文献   

The Behavior of Reinforced Concrete Members Under Combined Torsion and Shear     

Huang Shuzhi  Zhang Yu Zhu Guangli Senior engineer 《中国海洋工程》1995,(3)

- The behavior of the reinforced concrete members subjected to combined torsion and shear is studied in this paper. Based on the skew bending failure pattern observed in tests, and according to the gradual increase in strain on the concrete surface, a nonlinear full range analysis is performed for predicting the torque-twist relationship of members under combined torsion and shear for the ratio of torsion to shear is chosen bigger than 0.5 (T/ V b> 0.5). The test results are compared with the theoretical predictions.  相似文献   

High Performance Concrete and Its Typical Mixes     

Cai Yuebo  Kwan Kwokhung  Cheung Yaukai Chan Honchuen Senior Engineer  Material  Structure Department  Nanjing Hydraulic Research Institute  Nanjing P. H. Doctor 《中国海洋工程》1995,(3)

- With the modern development of chemical and mineral admixtures, it is now possible to produce much higher performance concrete than before. Higher performance does not only mean higher strength, but also better durability, lower risk of thermal cracking and higher dimensional stability etc. The three most effective admixtures for producing high performance concrete are superplastieizer, pulverized fuel ash and condensed silica fume. This paper outlines the properties of these materials and presents some practical guidelines for their usage.  相似文献   

Fatigue Properties of Plain Concrete Under Triaxial Compressive Cyclic Loading     

曹伟宋玉普  刘海成 《中国海洋工程》2004,18(3):457-468

Experiments were made on plain concrete subjected to triaxial static loading and constant-amphtude compressive fatigue loading with a constant lateral pressure in two directions. The initial confining pressure was O, O. lfc, O. 25fc and O. 4fc, respectively, for the static test, and O. lfc and O. 25fc for the fatigue test. Based on the triaxial compressive constitutive behavior of concrete, the inflexion of confining pressure evolution was chosen to be the fatigue damage criterion during the test. The rule of evolution of longitudinal maximum and minimum strains, longitudinal cyclic modulus and damage were recorded and analyzed. According to the Fardis-Chen criterion model and the concept of equivalent fatigue life and equivalent stress level, a unified S-N curve for multi-axial compressive fatigue loading was proposed. Thus, the fatigue strength factors for different fatigue loading cases can be obtained. The present investigation provides information for the fatigue design of concrete structures.  相似文献   

Stress Variation Model of Bond Stress-Slip Relationship Between Steel Bar and Concrete     

Song Yupu Zhao Guofan Doctor  Professor  Dalian University of Technology  Dalian Professor  Dalian University of Technology  Dalian 《中国海洋工程》1994,(1)

Based on the experimental data, a stress variation model of the bond stress-slip relationship between steel bar and concrete is established. The characteristic of the model is that the boundary conditions are satisfied very well; the effects of the material properties, the concrete cover, the crack spacing and the distance from the cracked cross section are considered. Good agreement between measured and calculated bond stress-slip relationship is found. This model is useful for the study of the stiffness, deformation and crack width of reinforced concrete members, and for the nonlinear analysis of reinforced concrete structures by the finite element method.  相似文献   

钢筋混凝土的腐蚀与防护     

王卫英  于志鹏  吕平  赵铁军 《海岸工程》2003,22(2):104-108

对混凝土和钢筋的腐蚀原因进行了分析，并提出了相应的防护措施．  相似文献   

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     

华渊  周太全  吕宝华 《岩土力学》2008,29(Z1):232-236

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.  相似文献