临轨深基坑多场景多种类清障施工技术应用研究

随着城市建设的不断发展,临轨深基坑工程日益增多,而在这些工程中,地下障碍物的存在给施工带来了极大的挑战。以凤凰广场人防工程施工项目为例,深入探讨了临轨深基坑多场景多种类清障施工技术的应用。通过对工程中不同区域、不同类型障碍物的清障施工方案进行详细分析,包括预清障方案、施工方法、对周边环境的保护措施等,总结出一套切实可行的临轨深基坑清障施工技术,为类似工程提供了宝贵的经验和参考。

临轨半圆形深大基坑支护结构分析

依托苏州某临轨半圆形深基坑工程,工程后期需要下穿隧道,在支护选型过程中,穿越隧道区域采用可回收的CSM工法桩且增大下穿区域支撑布置间距,其余区域采用灌注桩及三轴止水帷幕,对基坑开挖全过程进行数值模拟分析,并进行现场监测。结果表明:“伞形”支撑可充分利用半圆形基坑的拱效应,基坑支挡体系呈现圆弧区域变形小,直边区域变形大的特点,直边区域比拱形区域变形大12.5%左右,能较好地控制对基坑自身及周边环境的影响。

自平衡静载试验在临轨桩基检测中的应用

通过苏地2016-WG-76地块二期项目临轨桩基四根大直径灌注桩静载试验,介绍了自平衡法测试的试验原理、方法及求极限承载力的具体过程。试验结果表明,自平衡法能有效、可靠地检测临轨桩基承载力,为设计及后续验收提供参考。

地铁车站站台层临轨行区外走道消防疏散设计

地铁车站具有客流密集、空间狭长的特点,若发生火灾,可能造成严重的人员伤亡及财产损失。系统的消防设计是保证乘客安全、维护经济利益的重要环节。常规设计中,站台层设备区临轨行区走廊与公共区之间未进行防火分隔,存在安全隐患。文章基于现行规范及工程经验提出的两个解决方案,都可以从规范符合性上解决站台层设备区走道的消防疏散问题,保证其安全性和可靠性。虽然方案可能扩大车站规模,但相对消防安全而言是值得的。

Correlation of Critical Loci for Water-Hydrocarbon Binary Systems by EOS Based on the Multi-Fluid Nonrandom Lattice Theory

Quantitative representation of complicated behavior of fluid mixtures in the critical region by any of equation-of-state theories re-mains as a difficult thermodynamic topics to date. In the present work, a computational efforts were made for representing various types of critical loci of binary water with hydrocarbon systems showing Type II and Type III phase behavior by an elementary equation of state [called multi-fluid nonrandom lattice fluid EOS (MF-NLF EOS)] based on the lattice statistical mechanical theory. The model EOS requires two mo-lecular parameters which representing molecular size and interaction energy for a pure component and single adjustable interaction energy pa-rameter for binary mixtures. Critical temperature and pressure data were used to obtain molecular size parameter and vapor pressure data were used to obtain interaction energy parameter. The MF-NLF EOS model adapted in the present study correlated quantitatively well the critical loci of various binary water with hydrocarbon systems.

Research on Axial Trail of High-Speed Gas Painting Automizor

The non linear dynamic model is set up of one type of high speed painting automizor with gas supporting system. The stability of motion and dynamic response of the gas painting automizor system are studied over a relatively wide range of rotating speed by numerical analytic method, the critical velocity under working condition is found, and rotate stability and critical condition are discussed in theory. Furthermore, the range of the critical parameter of the system when Hopf bifurcation occurs and the law between axis trace and bearing clearance are acquired, too.

Wheel/rail dynamic interaction due to excitation of rail corrugation in high-speed railway

Characteristics of wheel-rail dynamic interaction due to the rail corrugation in a high-speed railway are analyzed based on the theory of vehicle-track coupled dynamics in this paper.Influences of the corrugation wavelength and depth on the wheel-rail dynamic performance are investigated.The results show that,under the excitation of a measured rail corrugation,the wheel-rail dynamic interaction of high-speed railway is enhanced obviously,and the high-frequency dynamic force between wheel and rail is generated,which has an obvious impact on the vibrations of the wheelset and rail,and little effect on the vibration of the frame and carbody.If the corrugation wavelength is shorter than the sensitive wavelength,the wheel-rail vertical force will increase with the growth of the corrugation wavelength,otherwise,it will decrease.However,the wheel-rail vertical force keeps increasing with the growth of corrugation depth.Furthermore,if the corrugation wavelength is shorter than the sensitive wavelength,the wheel-rail vertical force will increase with the decrease of the running speed,otherwise,it will decrease.It is also found that the critical wavelength of corrugation increases with the growth of the corrugation depth and the running speed,and the critical depth of corrugation is nonlinearly related to the sensitive wavelength.

Quasi Normal Sectors and Orbits in Regular Critical Directions of Planar System

This paper deals with the qualitative behavior of orbits at degenerate singular point with the method of quasi normal sector, which is a generalization of Frommer's normal sectors. Several examples show that this method is more effective than the wellknown methods of Z-sectors, normal sectors and generalized normal sector.

Homoclinic Flip Bifurcations Accompanied by Transcritical Bifurcation

The bifurcations of orbit flip homoclinic loop with nonhyperbolic equilibria are investigated. By constructing local coordinate systems near the unperturbed homoclinic orbit, Poincare maps for the new system are established. Then the existence of homoclinic orbit and the periodic orbit is studied for the system accompanied with transcritical bifurcation.