为合理评价隧道运营状况,基于运营隧道现场变形监测成果,先利用混沌理论、随机森林算法和支持向量机构建变形预测模型,再利用M-K检验等进行预测结果的可靠性验证分析,两者结合评价隧道运营状况.实例分析表明,在变形预测过程中,预测结果的平均相对误差均小于2％,具有较高的预测精度;同时,经可靠性验证,趋势判断结果与预测结果较为一致,均得出隧道变形仍会进一步增加,但增加速率变小,趋于稳定方向发展,即会维持现有运营状况.

为实现隧道变形的高精度预测,该文首先利用H-P滤波将隧道变形数据分解为趋势项和误差项;再利用优化深度神经网络构建趋势项预测模型,并将趋势项的预测误差与H-P滤波分解的误差项叠加,组成新的残差序列;最后,利用马尔科夫链进行了残差序列的弱化预测.实例分析表明:H-P滤波在隧道变形数据的信息分解方面,比传统小波具有显著的优越性,且预测结果的平均相对误差值约2％,具有较高的预测精度,通过外推预测,隧道变形呈小幅度增加趋势,说明其变形将向趋于稳定方向发展,验证了该断面支护结构体系的合理性和有效性.

为进行隧道大变形组合预测及稳定性评价的综合研究,该文先采用粒子群算法和遗传算法优化各模型的结构参数,得到参数优化后的单项预测模型,再利用非线性方法实现各单项预测结果的组合,构建出隧道大变形组合预测模型;其次,利用尖点突变理论分别对隧道大变形的现有监测数据和预测数据进行评价,以实现隧道大变形稳定性的现状评价和预测.实例分析结果表明:通过粒子群算法和遗传算法的参数优化,不仅能提高预测精度,还能提高预测结果的稳定性,且各断面组合预测结果的相对误差均小于2％,得出该组合预测模型具有较高的预测精度,在隧道大变形预测中具普遍适用性;同时,各断面的稳定性现状均处于稳定状态,可进行后期大变形的处理及施工.该文为隧道大变形处理提供了理论支撑和指导,具较好的实用性和有效性.

介绍武汉某预应力钢筋混凝土立交匝道静、动荷载试验内容、检测方法,通过预应力钢筋混凝土立交匝道进行试验分析,对桥梁结构的承载能力和工作状况做出综合评价,确保该桥能安全使用。

介绍武汉某预应力钢筋混凝土立主线变宽段静、动荷载试验内容、检测方法,通过预应力钢筋混凝土立交主线变宽段进行试验分析,对桥梁结构的承载能力和工作状况做出综合评价,确保该桥能安全使用。

本文介绍了浑水河大桥主桥荷载试验内容、检测方法,通过对凝土变截面箱型连续刚构进行理论计算和试验成果的对比分析,对桥梁结构的承载能力和工作状况做出综合评价,确保该桥能安全使用。

In order to study shearing characteristics of contact surface between clay and timber,direct shear test and simple shear test are separately conducted on the interface between clay and timber with original and refitted DSJ-2 electric quadruple iso-strain direct shear apparatus,and comparative analysis is also made.The result shows that under simple shear test,shearing strength on interface between clay and timber,i.e.shear displacement curve is inflexible in initial stage and composes of strain hardening section,strain softening section and plastic flow section after nonlinear elasticity stage.Under direct shear test,shearing strength is in hyperbolic relation.On that basis,this paper puts forward the conversion formula of interface shearing resistance index(interface shearing resistance index shall multiply the coefficient less than 1 under direct shear test) to correct direct shear test result in design.

80 soil-structure contact surface specimen tests are conducted by a refitted DSJ-2 electric quadruple equal stress direct shear device,which involve five contact types such as soil-soil,soil-smooth concrete,soil-rough concrete,soil-parallel veined wood,soil-vertical veined wood.As a result,shearing stress-strain curves for the contact interface between soil and different structures at various moistures and normal stresses are obtained.The result shows that the mechanical properties of soil-structure contact surface such as shear strength,friction angle and cohesion force are closely related with soil moisture,structure material and structure roughness.

对应变直剪仪进行改装,在改装后的剪切仪上进行了干燥及饱和的砂土同光滑及粗糙的钢材接触面的单剪试验。研究结果表明:当法向应力为50、100 kPa时,砂土与钢材界面剪应力、剪切位移关系曲线呈非线性关系;当法向应力为200、400 kPa时,呈刚塑性关系;不同基底情况下界面内摩擦角的变化与砂的粒径无很好的线性关系,在砂的粒径和基底粗糙度之间存在一个平衡点,当达到这个平衡点时界面抗剪强度达到最大值。

为了研究砂土与钢材接触界面剪切特性,对原有的及改装后的DSJ-2型电动四联等应变直剪仪上分别进行了砂土同钢材界面的单剪试验和直剪试验,并做了对比分析.研究结果表明:1)单剪试验下在法向应力50kPa、100kPa时,砂土与钢材界面的剪应力-剪切位移关系曲线呈非线性弹性理想塑性关系,在法向应力200 kPa、400 kPa时呈刚塑性关系.直剪试验下在法向应力50kPa、100kPa时,砂土与钢材界面的剪应力-剪切位移关系曲线呈非线性关系,在法向应力200kPa、400kPa时呈双曲线关系;2)提出了界面抗剪强度指标的经验换算公式(直剪试验下得到的界面抗剪强度指标乘以一个小于1的系数),以修正应用于设计的直剪试验结果.

The mechanical properties of limestone and sandstone under high temperature were investigated by the experiment device used to heat rock designed by ourselves and servo-control testing machine RMT-150C.The results show that the longitudinal wave velocity of two kinds of rocks gradually reduced with temperature increasing.The complete curve of stress and strain under uniaxial compression went through 4 stages,namely densification,elasticity,yielding and failure.They both displayed brittle fracture after reaching peak strength,with the sandstone rupturing and the limestone showing failure like a bundle of grass.The high temperature weakened their strength.Their peak stresses reduced with temperature increasing.At 700 ℃,the peak strength of limestone decreased by 84.59%,while that of sandstone only decreased by 22%.Their peak strain increased with temperature increasing,but differed in details.For limestone,its peak strain increased by 30.57% at 500 ℃,but almost kept unchanged at the higher temperature,and even shaw a little decrease at 700 ℃.For sandstone,however,the peak strain increased by 80.63% at 700 ℃,displaying a connection with the variation of microstructure.With temperature increasing,their elastic modulus and deformation modulus decreased.At 700 ℃,limestone decreased by 86.8% in elastic modulus and by 83.9% in deformation modulus,while sandstone decreased by 46.94% in elastic modulus and by 53.06% in deformation modulus.

It analyses the design theory of orthogonal test,researches the affection of nine affecting factors to the stability of clay slope by using the Bishop slice method of slope stability modular based on the orthogonal test,and deduces the order of the affecting degree of each affecting factor to the stability of clay slope.

When the thickness of transmission line regelation in frost or sleet weather more than the design value the following condition can occur: the conductor , ancher clamp ,pylon and so on cannot support the weight of sleet load and break fanilly. Such as the prong break of conductor, break of conductor, anchor clamp dropout, rupture, pylon lodge, local damaged and so on. The ice coating load that greater than design standard can lead the transmission tower break or collapse, the concrete type of action are differ. they can approximately split into the tower was crushed, failure by pull, torsion and unstability, draw and torsion break. From the structure form of transmission tower, the text discuss the reason of break due to sleet load and the basic protection form the aspect of mechanics.

Taking the demolition blasting for factory buildings in Datang Anyang power plant as sample,the method of air deck and short-delay blasting in building demolition was applied by analyzing the air deck and short-delay blasting principle.Through the experiment of local blasting,the vibration can be eliminated and a new method for building demolition blasting was explored.