无缝钢管坑式静压桩地基阻沉施工探讨

因某高层建筑整体向南倾斜,超过《建筑地基基础设计规范》(GB 5007-2011)的限值,采用坑式静压桩进行阻沉加固。本文就D402*10mm无缝钢管坑式静压桩的施工工艺以及施工过程中的主要问题和处理方法进行详细阐述,以期对类似的地基加固工程中坑式钢管静压桩施工提供参考。

上软下硬土层中沉井施工时克服阻沉的措施

沉井作为基础工程之一,得到了非常广泛地应用。就施工控制方面来说,沉井施工过程中最重要的就是预防突沉,控制超沉、阻沉及减少施工对地层的扰动。本文针对上软下硬土层的特点,分析了沉井施工时克服阻沉的措施。

沉夏通阻汤治疗梅核气60例临床观察

目的:观察沉夏通阻汤治疗梅核气的临床疗效。方法:选择梅核气患者120例,按随机数字表法分为对照组和治疗组各60例。对照组行半夏厚朴汤加减治疗;治疗组以沉夏通阻汤加味治疗。两组疗程均为20 d,比较临床疗效。结果:治疗后,治疗组总有效率90%,明显高于对照组73.3%,差异有统计学意义(P<0.05)。结论:沉夏通阻汤治疗梅核气可有效缓解咽部不适感,缩短病程,提高患者生活质量,是治疗梅核气的有效方剂。

某高层筏板基础纠倾迫降的设计与施工

根据沈阳某高层筏板基础的纠倾工程,对该建筑物采取的综合纠倾法进行了系统的研究。纠倾过程中遵循安全、协调、平稳、可控、环保的原则,首次采用在建筑物西北侧外增加阻沉桩,在外围其他部分设置侧限桩,并将原筏板基础向外扩大与阻沉桩相连,同时结合堆载预压法、排水固结法[1]、沟槽开挖、扰动沙石的方法进行纠倾迫降。最终使该高层建筑物逐渐回倾,南北方向的倾斜率由原来最大的3.23‰回倾至2.5‰以内,满足国家相关规范的要求。该工程不仅丰富和发展了在复合地基条件下高层建筑纠倾技术应用的空白,而且对今后高层建筑物的纠倾具有重要的借鉴意义。

高喷插芯组合桩在高层建筑纠倾加固中的应用

高喷插芯组合桩是一种用于建筑物地基处理的新型组合桩。结合沈阳某高层建筑纠倾加固工程实例,对造成建筑物倾斜的原因进行了分析,并阐述了高喷插芯组合桩的荷载传递机制与加固原理、设计和施工。最后,针对施工前后的加固效果进行了对比,确保后期纠倾迫降工程的安全实施。

某高层筏板基础建筑纠倾迫降技术分析

根据沈阳某高层筏板基础建筑成功纠倾的工程实例,对该工程采取的纠倾方案及纠倾过程进行技术和理论分析,论述高层建筑纠倾方面的最新研究和实践成果,探索采用在建筑物周围布置起保护作用的侧限桩和阻沉桩,并结合综合纠倾法对建筑物进行迫降。对高层建筑纠倾过程中的沉降监测数据进行成果分析,并依据数据的信息判断纠倾方案的可行性。通过该工程在复合地基条件下的纠倾实践,总结高层筏板基础建筑纠倾迫降技术的准则和方法,为高层筏板基础建筑纠倾迫降提供参考和借鉴。

某自建住宅楼纠偏加固方案

以实际工程为例,通过对自建建筑物现状的调查和加固方案的分析,总结了建筑物发生不均匀沉降、倾斜的原因,进而对阻沉桩进行了设计计算。针对深厚高压缩性土层和邻近不同时期修建的房屋产生的附加应力现象,提出了高压冲水法的纠偏施工方法;介绍了具体的施工方案,并在自建危房纠偏和加固中进行了应用,施工结果表明大大减少了掏土施工的难度和工程量,证明了方法的可行性。

Calculation mode of side friction for large open caisson

To overcome the problems in design methodologies and construction control measures for the large open caisson, systematic research was conducted on the side friction calculation mode of the large open caisson. Based on the field monitoring data of lateral soil pressure on the side wall of the open caisson for the southern anchorage of the Maanshan Yangtze River Highway Bridge, the statistical result of the side friction under different buried depths of the cutting edge of the open caisson was back-analyzed; and the side friction distribution of the large open caisson was underlined. The analysis results indicate that when the buried depth of the cutting edge is smaller than a certain depth H0, the side friction linearly increases with the increase in the buffed depth. However, as the buffed depth of the cutting edge is larger than H0, the side friction shows a distribution with small at both ends and large in the middle. The top of the distribution can be regarded as a linear curve, while the bottom as a hyperbolic curve. As the buffed depth of cutting edge increases continuously, the peak value of the side friction linearly increases and the location of the peak value gradually moves down. Based on the aforementioned conclusions, a revised calculation mode of the large open caisson is presented. Then, the calculated results are compared with the field monitoring data, which verifies the feasibility of the proposed revised calculation mode.

Electrodeposition and corrosion behavior of nanostructured Ni-TiN composite films

The Ni-TiN nanocomposite film was successfully electrodeposited on brass copper substrates.The microstructures of the Ni-TiN nanocomposite film were investigated using scanning electron microscopy（SEM） and transmission electron microscopy（TEM）.Its average grain size was analyzed through X-ray diffraction（XRD）,and its anti-corrosion property was studied through potentiodynamic scanning curves and electrochemical impedance spectroscopy（EIS）.The results show that the morphology of Ni-TiN composite film is sensitively dependent on the electroplating current density,TiN nanoparticle concentration,solution stirring speed,bath temperature and pH value of solution.The average grain size of the optimized nanocomposite film is about 50 nm.Meanwhile,the Ni-TiN nanocomposite films are much more resistant to corrosion than pure Ni coatings.

Micro arc oxidation and electrophoretic deposition effect on damping and sound transmission characteristics of AZ31B magnesium Alloy

Micro arc oxidation(MAO) and electrophoretic deposition(EPD) process are employed to fabricate a dense coating on magnesium alloy to protect it from corrosion in engineering application. The EPD film changes the damping characteristic of magnesium alloy, and both the MAO and EPD process change the bending stiffness of samples being treated. Damping loss factor(DLF) test and sound transmission experiments were carried out for AZ31 B magnesium alloy with coating fabricated by MAO and EPD processes. The results indicate that DLF is improved in frequency range from 0-850 Hz. Bending stiffness of the samples is improved with MAO and EPD treatment. As a result, the sound transmission loss(LST) is improved in the stiffness control stage of the sound transmission verse frequency curve. To the samples by electrophoresis process, the LST is improved in frequency range from 2500-3200 Hz, because the damping loss factor is improved with EPD process. The results are useful for the surface treatment to enhance the damping loss factor, LST and widespread application of magnesium alloy while improving the corrosion resistance.

Hybrid functional IrO_2-TiO_2 thin film resistor prepared by atomic layer deposition for thermal inkjet printheads

IrO2-TiO2 thin films were prepared by atomic layer deposition using Ir（EtCp）（COD） and titanium isopropoxide （TTIP）. The resistivity of IrO2-TiO2 thin films can be easily controlled from 1 500 to 356.7 μΩ·cm by the IrO2 intermixing ratio from 0.55 to 0.78 in the IrO2-TiO2 thin films. The low temperature coefficient of resistance（TCR） values can be obtained by adopting IrO2-TiO2 composite thin films. Moreover, the change in the resistivity of IrO2-TiO2 thin films was below 10% even after O2 annealing process at 600 ℃. The step stress test results show that IrO2-TiO2 films have better characteristics than conventional TaN08 heater resistor. Therefore, IrO2-TiO2 composite thin films can be used as a heater resistor material in thermal inkjet printhead.

Study of the Corrosion Resistance of Electroless Ni-P Deposits in a Sodium Chloride Medium

The corrosion resistance of electroless Ni-P deposits with phosphorous contents from 12% to 14% in sodium chloride solutions was studied. The deposits were immersed in 3.5% NaCl solutions for 29 d to obtain the electrochemical parameters and were examined in a standard salt spray test for 15 d respectively. The corrosion resistance of the deposits was studied by poten- tio-dynamic scan, electrochemical impedance spectroscopy (EIS), X-ray diffraction (XRD) and cold-field emission scanning electron microscopy (FE-SEM) equipped with an energy dispersive X-ray detector (EDX). The patterns of XRD and the results of FE-SEM showed that the prepared deposits were amorphous. But after a 15 d standard salt spray test, a few pinholes appeared on the surface of the deposit and the weight content of phosphorus on the surface of the deposit was higher (which was beneficial to the formation of the passivation films) than that before the standard salt spray test when the nickel content was lower because the dissolved weight of nickel was greater than that of phosphorus. The results from potentio-dynamic scan and EIS showed that passivation films formed on the Ni-P deposit after immersion in the NaCl solutions, which decreased the corrosion rate of Ni-P samples. The results of this work show their potential applications in marine corrosion.

Study of Cobalt Electrodeposition onto Stainless Steel Using Electrochemical Impedance Spectroscopy （IES）

This paper describes the study of cobalt growth mechanism obtained by electrodeposition method with variation of pH solution. The electrochemical impedance spectroscopy （EIS） and scanning electronic microscopy （SEM） results were possible conclude that the cobalt electrodeposited at pH = 5.40 presented approximately an area three times larger than the cobalt electrodeposited at pH = 2.70. In addition, the cobalt electrodeposited at pH = 2.70 had a value of charge transfer resistance equal to 151.6 f2＂cm2 and the cobalt electrodeposited at pH = 5.40 this value corresponds to 67.4 f2＇cm. This occurs because the increased in micro-porosity increase the diffusion of electrolyte on cobalt electrodeposits easily the corrosion process.

Conceptual Design of a Deep Draft Semi-Submersible Platform with a Moveable Heave-Plate

Based on the principle of turned mass damper(TMD) systems,the conceptual design of semi-submersible platform with a moveable heave-plate(MHS) has been put forward.The heave motion response amplitude operator(RAO) and viscous damping of the MHS platform are calculated by iteration,and the coupling stiffness between the MHS hull and the heave-plate is optimized to decrease the maximum heave motion response of the MHS hull under 10-year survival conditions in the South China Sea.The nu-merical results indicate that the heave motion RAO of the MHS hull can be decreased in the range of predominant wave frequencies,which may provide some reference to the heave motion control of offshore platforms.

General formulas for drag coefficient and settling velocity of sphere based on theoretical law

The settlement of particles is of great importance in many areas. The accurate determination of drag coefficient and settling velocity in wide Reynolds number （Re） range remains a problem. In this paper, a series of new formulas for drag coefficient of spherical particles based on theoretical laws, such as the Stokes law, the Oseen law, and the Goldstein law, were developed and fitted using 480 groups of experimental data （Re 〈 2 × 10^5）. The results show that the 2nd approximation of a rational function containing only one parameter can describe Co-Re relationship accurately over the whole Re range of 0-2× 10^5. The new developed formulas containing five parameters show higher goodness over wide Re range than presently existing equations. The introduction of the Oseen law is helpful for improving the fitting goodness of the empirical formulas. On the basis of one of the Oseen-based Co-Re formulas giving the lowest sum of squared relative errors Qover the whole Re range （Re 〈 2 × 10^5）, a general formula for settling velocity ut based on dimensionless parameters was proposed showing high goodness.

Monitoring the Morphology of the Bottom of Streams and Reservoirs Using Electrical Impedance Spectrometry Method

A part of the Earth＇s surface has been formed by the action of running water during geomorphological development. The flow of water is one of the ways of how particles can be eroded, transported and accumulated. If endogenous processes do not work, the surface of the continents would lower to the level close to the ocean surface and the relief would have almost no ruggedness. Recently, there have been talks about the relative classification of deviation of the present state from the ＂original＂ or ＂natural＂ one caused by anthropogeneous effects. The activity of man can manifest itself by pollution, the excessive use of water, a change in the flow regime, and the like. Research into the morphology of the river bottom and the bottom of settling tanks or dam reservoirs is systematically carried out in selected streams and reservoirs by the long-term sampling of bottom sediments. The knowledge of the sediment layer is also important. The EIS method, which was used for measuring, is new for the aforementioned applications. Possibilities of EIS method with new apparatus using for this application were tested in laboratory and in situ. On the basis of interpretation of the electrical conductivity data, a grid of depth data was acquired. These data are characterized by anomalously high and low ＂spots＂ and show morphological changes in the studied area.

Catalyst-Free Growth of Nanographene Films on Various Substrates

We have developed a new method to grow uniform graphene films directly on various substrates, such as insulators, semiconductors, and even metals, without using any catalyst. The growth was carried out using a remote plasma enhancement chemical vapor deposition （r-PECVD） system at relatively low temperatures, enabling the deposition of graphene films up to 4-inch wafer scale. Scanning tunneling microscopy （STM） confirmed that the films are made up of nanocrystalline graphene particles of tens of nanometers in lateral size. The growth mechanism for the nanographene is analogous to that for diamond grown by PECVD methods, in spite of sp2 carbon atoms being formed in the case of graphene rather than sp3 carbon atoms as in diamond. This growth approach is simple, low-cost, and scalable, and might have potential applications in fields such as thin film resistors, gas sensors, electrode materials, and transparent conductive films.