Sinking of piles by impression

Theoretical and experimental investigations of the use of impressed piles to strengthen the beds of foundations of buildings and eliminate their dangerous settlement caused by errors in design and work production are presented. The high efficiency of this method is demonstrated. Translated from Osnovaniya, Fundamenty i Mekhanika Gruntov, No. 3, pp. 25–27, May–June, 1997.     

谈夯扩桩在高层建筑中的应用

本文通过三明建设大厦采用夯扩桩基的实例，试桩验证及建筑物最终沉降的观测分析认为：只要采用一些合理的施工工艺措施和严格的质量管理，锤击沉管夯扩桩应用于高层建筑的基础工程是可行的，且具有较好的经济效益。     

聚合物泥浆在钻孔灌注桩中的相关应用

对聚合物泥浆目前在钻孔灌注桩领域的应用情况进行了分析,结合工程实践及现场试验,总结了聚合物泥浆在钻孔灌注桩领域施工的相关技术控制要点,通过对比聚合物泥浆与传统的泥浆,得出了聚合物泥浆的优越性与局限性。     

高聚物碎石桩模型试验及数值分析

为了使新型的高聚物碎石桩在工程中的应用和推广,通过对3种不同高聚物密度的高聚物碎石桩模型分别进行了模型试验和有限元扩展分析,研究了其承载特性。结果表明:高聚物碎石桩的承载能力分别随着高聚物密度、桩长、桩径的增加而增加;在同一级桩顶荷载作用下,得到模型桩的桩侧摩阻力会随着高聚物密度的增加而增大;在相同高聚物密度下,得出桩径越大,桩端阻力的荷载分担比越小。另外,高聚物碎石桩的承载能力优于碎石桩和CFG桩。     

Swelling properties and coefficient of permeability of friction-reducing polymer for pull-out of temporary sheet piles

Harmful cracks and settlements occur after the pull-out removal of temporary sheet piles. This is because a large amount of soil is discharged from the ground due to the significant skin friction at the steel surface. In order to prevent these cracks and settlement problems, a friction-reducing polymer was developed. After a sheet pile coated with the polymer is installed into the ground; the polymer absorbs ground water and transforms to a swollen gel layer which separates the soil and the sheet piles. In this investigation, a newly designed column type test apparatus was used to simulate ground conditions. The swelling test was carried out, followed by a continuous permeability test. Based on the obtained test results, the swelling properties and coefficient of permeability of the friction-reducing polymer in the ground were determined. The main conclusions are as follows. The values of the water-absorbing ratio, Ra_max, decrease with increasing earth pressure, p′, independent of the pore water pressure, u. Equations to determine the values of Ra_max are proposed as functions of p′ only. The maximum swelling pressure, at which the friction-reducing polymer cannot absorb water and swell, is p′_max?=?560?kPa. Even at a depth of approximately 100?m, the polymer absorbs ground water, and the swollen gel layer forms. The approximate range of coefficient of permeability, k, of the swollen gel layer is 10^?13–10^?11 m/s; these are extremely small values. The swollen gel can be considered an impermeable material. Depth distributions of the thickness and the coefficient of permeability of the swollen gel layer are illustrated in practical charts, based on the test results.     

水力机械法下沉沉井

通过对某江边水泵房沉井施工的总结，论述采用水力机械法下沉沉井的施工方法和注意事项。     

时空效应原理在沉井中的应用

通过上海市富锦路地道雨水泵站沉井施工,介绍了原定湿沉成井改为干沉后,施工中采取的纠偏、封底等措施。着重阐述了软土工程中时空效应原理和在沉井工艺中的应用。经实践,沉井完全达标,对周围构筑物与管线没有影响,而且节约了1个月的施工期和40万元。     

用气囊进行过江管道沉管施工的工程实践

本文通过工程实例,介绍过江管道海上浮运、连接与沉放过程,对类似工程施工具有一定的借鉴意义.     

沉管管桩贯入度的准确控制

结合工程实例,分析了影响沉管管桩贯入度的因素,介绍了沉管管桩贯入度施工设计方法并与实际控制结果进行了比较。提出了提高贯入度控制准确性的实用方法。     

下沉式抗滑桩的设计

本文主要针对下沉式抗滑桩提出了简化计算方法,并以实际说明了在滑坡治理工程中采用下沉式抗滑桩有较显著的经济效益。     

局部加劲钢套管加固钢筋混凝土柱的研究

本文介绍了一种改进的钢套管加固现有柱的方法,将薄钢板焊接成一个环箍套管,以提高柱的抗剪强度,然后可选择不同类型的约束部件(加劲元件)焊接在可能产生塑性铰的部位,以增加柱的延性。所提出的设计计算方法通过了5根1/3比例的模型柱试验验证,试验加载条件为在0.3Af'的固定轴力下,施加水平往复荷载。试验结果表明:局部加劲钢套管不仅可以预防脆性的剪切破坏,还可以大幅提高柱的延性,可使最大侧移率超过8%。该加固方法可使方形或矩形截面混凝土柱的强度与延性得到良好的改善。c     

“T”形沉井的下沉施工技术

1 工程概况 浙江省温州市某污水处理厂工程位于温州市燕化镇桃花岛以南,蒲州河以东,团江西岸,该污水处理厂工程的粗格栅间及进水泵房采用沉井结构,该沉井平面形状为“T”形(见下图),其中“T”形的“-”部分为进水泵房,“I’部分为粗格栅间。 该沉井外包尺寸为30100×1933mm,“T”形肋宽为10900mm,面积约为400m~2;沉井进水泵房高度为     

圆形截面玻璃纤维筋混凝土桩体抗剪承载力研究

用GFRP筋来部分代替钢筋或预应力钢筋用于混凝土结构中,国内外已有大量研究和应用。目前对玻璃纤维（GFRP）筋混凝土结构受剪性能的研究,主要都是尺寸较小的矩形截面梁,关于圆形截面构件的斜截面受剪承载力的研究却极少。根据实际工程桩尺寸首次制作了比例为1∶1的试件,进行了二集中力三分点加载试验,试验中发现玻璃纤维筋混凝土梁具有剪切破坏的特征,通过对试验结果的分析并结合美国ACI规范与中国混凝土设计规范中抗剪承载力公式,推导出圆形截面GFRP筋混凝土梁的抗剪承载力公式,采用该公式计算的结果与实测值非常相近。进一步将上述理论应用在北京某地铁车站的基坑围护桩中,校核计算了盾构接收过程中围护桩的安全性,据此提出增大配筋率的建议。     

大桥加固过程中新桩对已有桩基影响研究

结合某桥梁加固工程实例,探讨了新桩施工与冲孔挤土对已有桩基的影响,分析了新桩施工过程中已有桩基弯矩承载力,得出了一些结论,为工程施工提供了依据。     

Analysis of piles in rock

A review of research on the performance of piles in rock is presented. It is demonstrated that the bearing capacity of a pile is determined not only by the uniaxial compressive strength of the rock in its bed, but also by such factors as the ratio of the diameter of the pile to the depth of its embedment, the ratio of the compression modulus of the rock mass to the elastic modulus of the concrete pile, and the conditions at the contact between the lateral surface of the pile and rock, as well as procedural characteristics of the work performed in installing the piles. __________ Translated from Osnovaniya, Fundamenty i Mekhanika Gruntov, No. 1, pp. 8–12, January–February, 2007.     

基桩高应变动力检测在工程桩检测中的应用

介绍了基桩高应变动力检测的测试原理，并引用工程实例加以阐述，通过对试验过程及其结果的分析证明，此法能够有效地补充和部分取代静载荷试验，在节约费用、提高效率的情况下还能很好地保证质量。