高山峡谷地区大跨度桥梁岸坡稳定性分析、趋势预测及应用研究

In order to realize fast development of the national economy in a healthy way and coordinate progress with whole society, the country has implemented the strategy of development of the western region. An important action of finishing this strategic task is to accelerate the highway construction in the western region, join the western region and places along the coast, the river, the border with goods and materials, technology, and personnel interchanges, and then drive development of the local economy.The western region was influenced by the Himalaya Tectonization in Cenozoic, and the crust rose and became the plateau. In the course of rising, rivers cut down sharply to form a lot of high mountains and gorges.Because of topography and geomorphology, bridges in the traffic construction in the alpine gorge area are needed. Rivers have characteristics of large flow, fast velocity and high and steep river valley, so building a pier in the river is not only very difficult, but also making the cost increase. At the same time, the impact that the pier is corroded and the bridge base that is drawn to be empty by flow are apt to cause destruction of the pier. For those reasons, suspending bridge and cable-stay bridge are usually adopted with the single and large span. For the large span bridge, the pier foundation could receive ten thousand and more vertical strength, bending moment and near kiloton horizontal thrust.Because bank slope in the alpine gorge district is cut deeply and unsettled big, natural stability is worse under endogenic and exogenic force. When bank slope bears heavy vertical strength, bending moment and horizontal thrust facing the river, it will inevitably make the balance state of rock and soil mass change, bridge bank slope deform, and even destroyed. So the key problem at the time of the large span's bridge construction in the alpine gorge area is how to make it stable.So based on the spot investigation, the Engineering Geology Analysis Method is very important to grasp the bank slope stability. It can provide the bank slope stability macroscopic ally and qualitatively, and reference to the indoor calculation. The Engineering Geology Analysis Method is that by way of analyzing and investigating terms of bank slope instability, stability development trend, the ancient rock slide and devolution in the site, stability comprehensive evaluation primarily, current and future stability of bank slope is gotten, realizing the intention to serving the concrete engineering.After the Engineering Geology Analysis Method is applied to project instances of BeiPan River Bridge and BaLin River Bridge, results are accord with bank slope actual conditions, which proves sites are suited to building bridges from site stability.we often meet bank slope stability issues in the traffic construction in the alpine gorge areao Before the evaluation of the bank slope stability, the engineering geological condition is investigated first. After that, the next exploration target and geology measures are decided. So, the Engineering Geology Analysis Method that the investigation of the engineering geological condition is the main content is quite important in practice. The other evaluations of the bank slope stability are based on it. Because foundation receives very heavy load, for the big span's bridge in the alpine gorge area, a long pile of the large diameter (D^0.8m) is usually selected. In order to reflect rock mass's deformation properties under rock-socketed pile function, the author has used the FLAG30 software for rock and soil mass and done many numerical simulations. By them, the author launches the further investigation on deformation properties of bank slope under different slope angle, pile length, diameter, elastic modulus, load, bank slope's structure, etc. Some conclusion meaningful to the design and produce are obtained.

分子水平上研究地质流体的物理化学性质

Geological fluids exist in every geosphere of the Earth and play important roles in many processes of material transformations, energetic interchanges and geochemical interactions. To study the physicochemical properties and geochemical behaviors of geological fluids turn Girt to be one of the challenging issues in geosciences. Compared with conventional approaches of experiments and semi-theoretical modeling, computer simulation on molecular level shows its advantages on quantitative predictions of the physicochemical properties of geological fluids under extreme conditions and emerges as a promising approach to find the characteristics of geological fluids and their interactions in different geospheres of the Earth interior.This dissertation systematically discusses the physicochemical properties of typical geological fluids with state-of-the-art computer simulation techniques. The main results can be summarized as follows: (1) The experimental phase behaviors of the systems CH4-C2H6 and. CO2 have been successfully reproduced with Monte Carlo simulations. (2) Through comprehensive isothermal-isobaric molecular dynamics simulations, the PVT data of water hia^e been extended beyond experimental range to about 2000 K and 20 GPa and an improved equation of state for water has been established. (3) Based on extensive computer simulations, am optimized molecular potential for carbon dioxide have been proposed, this model is expected to predict different properties of carbon dioxide (volumetric properties, phase equilibria, heat of vaporization, structural and dynamical properties) with improved accuracies. (4) On the basis of the above researches of the end-members, a set of parameters for unlike interactions has been proposed by non-linear fitting to the ab initio potential surface of CO2-H2O and is superior to the common used mixing rule and the results of prior workers vs/Ith remarkable accuracies, then a number of simulations of the mixture have been carried out to generate data under high temperatures and pressures as an important complement to the limited experiments. (5) With molecular dynamics simulations, various structural, dynamical and thermodynamical properties of ionic solvations and associations have been oomprehensively analyzed, these results not only agree well with experimental data and first principle calculation results, but also reveal some new insights into the microscopic ionic solvation and association processes.