碎石桩是一种常用的地基处理方式,其振动挤密施工会对桩周土产生一定程度的扰动效应,但现有关于碎石桩振动扰动效应的研究较少.通过埋设孔隙水压力计、土压力盒、测斜管,并结合静力触探试验,研究了碎石桩施工过程中桩周土中的孔隙水压力、土压力、深层水平位移和强度变化规律.研究结果表明:碎石桩施工时会在桩周土中产生较大的孔隙水压力和深层水平位移,随着孔隙水压力的消散,桩周土中的附加有效应力增加,土体的强度得到一定程度的改善.

Stone column is commonly used in foundation treatment. Till now,there is little research about the construction influence of stone column. The pore water pressure,earth pressure,deep horizontal deformation and strength during construction process of surrounding soil were respectively measured by piezometers ,pressure transducers,inclinometers and CPT. The field test results show that there were large pore water pressure and deep horizontal deformation due to stone column construction. The effective stress and strength of surrounding soil increased with the dispassion of pore water pressure.

在自主研制的孔隙介质热-水-应力耦合有限元程序中引入Taron等提出的颗粒聚集体的压力溶解模型,针对一个假设的实验室尺度且位于非饱和石英颗粒聚集岩体中的高放废物地质处置模型,拟定两种计算工况:(1)孔隙率和渗透系数是压力溶解的函数;(2)孔隙率和渗透系数均为常数,进行4 a处置时段的数值模拟,考察了岩体中的温度、颗粒界面水膜及孔隙中的溶质浓度、迁移和沉淀质量、孔隙率及渗透系数、孔隙水压力、地下水流速和应力的变化、分布情况。研究结果表明:工况1计算终了时,压力溶解使得孔隙率和渗透系数分别下降到初始值的43%~54%、4.4%~9.1%。在核废料释热温度场的作用下,工况1、2中的负孔隙水压力分别为初始值的1.00~1.25倍、1.00~1.10倍,前者表现了压力溶解的明显影响;两种工况的岩体中的应力量值及分布基本相同。

The model of pressure solution for granular aggregates established by Taron et al is introduced into the FEM code for analysis of thermo-hydro-mechanical coupling in porous media developed by the first author. Aiming at a hypothetical model for nuclear waste disposal in an unsaturated quartz aggregate rock mass with a laboratory scale, two computational conditions are designed: (1) the porosity and the permeability of rock mass are functions of the pressure solution; (2) the porosity and the permeability are constants, then the corresponding numerical simulations for a disposal period of 4 years are carried out; and the states of temperatures, solute concentrations in the intergranular fluid film and at the pore space, removal and precipitation masses, porosities and permeabilities, pore pressures, flow velocities and stresses in the rock mass are investigated. The results show:at the end of the calculation in case 1, pressure solution makes the porosities and the permeabilities decrea

为揭示不同埋深岩溶陷落柱在承压水压力和压实程度2种影响因素作用下的突水机理,利用改进的变质量破碎岩石渗流试验系统,进行了考虑颗粒迁移的破碎泥岩变质量渗流试验,得出渗流突变历时、突出物质量、突出物质量变化率及孔隙度变化率等在渗透压力和初始孔隙度共同作用下的变化规律。研究表明:1)在渗流初始阶段,渗透压力和流量稳定;渗流突变时,渗透压力和流量均发生剧变,变化幅度与试样的突出物质量和孔隙结构调整情况有关。2)随初始孔隙度增大、渗透压力增加,突水历时变短,突出物质量增大,二者均可由渗透压力和初始孔隙度表示为对数函数,突出物质量变化率和孔隙度变化率均变快,可用指数函数拟合。3)随着渗透压力增大,突水历时、突出物的质量、突出物质量变化率和孔隙度变化率受初始孔隙度的影响逐渐减弱。

In order to study the water inrush mechanism of Karst collapse column in different depths with coupled underground water pressure and compaction degree, a modified variable mass seepage experiment system on broken rock was used to conduct variable mass seepage experiments for broken mudstone considering particle migration. The duration time of seepage burst, weight of gushed particle, change rate of gushed particle weight and change rate of porosity were recorded and calculated, and the change rules under seepage pressure and initial porosity were obtained. It shows that in the initial seep-age stage, seepage pressure and flow are stable, they change rapidly when seepage burst happens, and the change range is related to weight of gushing particle and the process of pore structure adjusting. With the initial porosity and seepage pressure increasing, the duration time of seepage burst gets shorter,weight of gushed particle gets larger, and these two parameters are fitted by logarithmic f

半直立式圆筒护岸是一种新式港口工程结构,结合其在大连某水工护岸工程中的应用,进行了半直立式圆筒护岸地基的加载试验,通过实测土压力、沉降、水平位移及孔隙水压力,分析了半直立式圆筒护岸地基的沉降及水平位移变化特点,并进一步研究了其不均匀沉降的发展过程.试验结果表明:半直立式圆筒护岸沉降及水平位移对护岸荷载分级、每级荷载加载量、加载历时及两级荷载之间的间隔时间较为敏感,其中护岸后方最后一级不对称加载对圆筒结构的不均匀沉降影响最大,孔隙水压力变化主要受每级加载量、加载历时及潮汐作用影响,而圆筒安装及第一级荷载施加后,孔隙水压力产生较大的波动.

@@@@Semi-vertical cylindrical revetment is a new port engineering structure. Field load tests on a semi-vertical cylindrical revetment is carried out based on its application of a hydraulic revetment in Dalian. The earth pressure, foundation settlement, horizontal movement and pore water pressure of the semi-vertical cylindrical revetment are monitored. The settlement and horizontal movement of foundation of the semi-vertical cylindrical revetment are analyzed, and its non-uniform settlement is further studied. The monitoring results indicate that the sensitive factors affecting the settlement of the semi-vertical cylindrical revetment are loading stage, loading intensity, loading duration and loading intervals. The final unsymmetrical loading behind the revetment has the greatest impact on the non-uniform settlement of cylindrical structure. The variation of pore water pressure is mainly affected by each loading, loading duration and tidal action. When the cylindrical structure is ins

为了研究静力触探试验及沉桩扩孔等工程问题，基于修正剑桥模型，推导了不排水条件下球孔扩张问题的半解析解。将扩张球孔周围土体分为临界状态区、塑性区以及弹性区三个区域。弹性区内，利用弹性理论得到应力和孔隙水压力的解答；临界状态区及塑性区内，利用相关联的流动法则、拉格朗日分析法建立了关于应力的一阶非线性常微分方程组，以弹塑性界面处的应力分量作为初值，求解微分方程组可得到应力和孔隙水压力的解答。研究结果表明：各向同性超固结比对扩孔压力、土体应力、超孔隙水压力以及塑性区范围均具有显著影响，且扩孔过程中土体剪切模量并非常量，其随扩孔半径、各向同性超固结比的变化而变化；同时通过与已有解答进行比较，对本文方法的可靠性进行了验证。

An exact semi?analytical solution in the undrained cavity expansion can be obtained on the basis of the MCC model to research the cone penetration test and the pile driving. The field around the cavity can be divided into three zones: critical zone, plastic deformation zone and elastic deformation zone. In the elastic zone, an analytical solution for the distributions of stress and excess pore pressure is deduced according to the elastic theory. In the critical and plastic zone, a set of first?order nonlinear ordinary differential equations concerning stress can be obtained according to the associated flow rule and the lagrangian analysis method. The stressss and pore pore pressure can be solved as an initial value problem starting at the elastic?plastic boundary. The results show that the isotropic over consolidation ratio has a significant influence on the stresses and the excess pore pressure.The shear modulus vary significantly with the cavity radius and the isotropic ove