The concrete should have good and durable engineering property under the ideal condition , but due to the environmental or working reasons , the surface is easily corroded , and even cracked to expedite the neutralization by the co2 and speed the corrosion on steels , and finally to cause the durability problem 摘要在理想状态下，混凝土应具有良好且耐久的工程性质，然受到外在环境或施工等因素影响，混凝土表面易受侵蚀而破坏，甚至于当表面发生龟裂后，二氧化碳使得中性化的现象加速，造成钢筋的腐蚀速度增快，易引起混凝土耐久性的问题。
Five factors of effecting specify the bearing capacity of drilled grouting pile ( engineering properties of soil , structural dimension of pile , stiffness of pile , time ) have been concluded through introducing the transmission of load mechanism of drilled grouting pile . at the same time , the effecting parameter has been collected . the paper build the ann model in predicting ultimate bearing capacity of drilled grouting pile and discuss in detail the extraction of inputting nodes information when quoting the fundamental principle of ann model and introducing research process of the improved bnn 本文简要介绍了桩基承载力的研究现状并指出将神经网络引入桩基工程的意义，从介绍单桩荷载传递机理出发总结了影响单桩极限承载力的五种因素(桩周土的工程性质、桩身结构尺寸、桩的刚度、时间以及施工工艺)并提取了相应的参数；引用神经网络基本原理，详细介绍了改进bp神经网络的研究过程，从而建立了预测钻孔灌注桩极限承载力的神经网络模型；并详细讨论了本模型的神经网络输入结点信息的提取，在工程实例的基础上进行了数值计算。
Analyzing quantitatively the structural features of soft soil from marine accumulation around vacuum preloading by means of x - ray , scanning electronic microscope and computer image processing technique , together with the experiment and comparing the changes of soft soil in microstructure and engineering properties , the authors studied the consolidation mechanism of vacuum preloading 摘要借助x -射线、扫描电镜及计算机图像处理等技术，对海积软土真空预压加固前后的结构特征进行定量分析，并结合室内试验，对比研究土体微观结构和工程性质的变化，探讨真空预压加固的机理。
