In the construction of high dams, many high rock slope failures occur due to flood discharge atomized rain. Based on the steel frame lifting technique and strength reduction materials, a comprehensive method is proposed in this paper to study the stability of high bedding rock slope subjected to atomized rain. The safety factor expression of the comprehensive method and the evaluation method for deformation instability were established according to the similarity theory of geomechanical model, failure criterion, and mutation theory. Strength reduction materials were developed to simulate the strength reduction of structural planes caused by rainfall infiltration. A typical test was carried out on the high bedding rock slope in the Baihetan Hydropower Station. The results showed that the failure modes of the bedding rock slope were of two types: sliding–fracturing and fracturing–sliding. The first slip block at the exposed place of the structural plane was sliding–fracturing. Other succeeding slip blocks were mainly of the fracturing–sliding type due to the blocking effect of the first slip block. The failure sequence of the slip blocks along the structural planes was graded into multiple levels. The slip blocks along the upper structural planes were formed first. Concrete plugs had effective reinforcement to improve the shear resistance of the structural planes and inhibit rock dislocation. Finite element method (FEM) simulation was also performed to simulate the whole process of slope failure. The FEM simulation results agreed well with the test results. This research provides an improved understanding of the physical behavior and the failure modes of high bedding rock slopes subjected to atomized rain.

For deep-water faulted sandstone reservoirs, the general practice is to design long horizontal wells improving well productivity. During the project implementation stage, well tests are performed on all drilled wells to evaluate well productivity accurately. Furthermore, multisize chokes are often utilized in a shorten test time for loosen formation, high test cost, and high well productivity. Nevertheless, the conventional productivity evaluation approach cannot accurately evaluate the well test productivity and has difficulty in determining the underneath pattern. As a result, the objective of this paper is to determine a productivity evaluation method for multisize chokes long horizontal well test in deep-water faulted sandstone reservoir. This approach introduces a productivity model for long horizontal wells in faulted sandstone reservoir. It also includes the determination of steady-state test time and the productivity evaluation method for multisize chokes. In this paper, the EGINA Oilfield, a deep-water faulted sandstone reservoir, located in West Africa was chosen as the research target. Based on Renard and Dupuy’s steady-state equation, the relationship between the productivity index per meter and the length of horizontal section was derived. Consequently, this relationship is used to determine the productivity pattern for long horizontal wells with the same geological features, which can provide more accurate productivity evaluations for tested wells and forecast the well productivity for untested wells. After implementing this approach on the EGINA Oilfield, the determined relationship is capable to accurately evaluate the test productivity for long horizontal wells in reservoirs with similar characteristics and assist in examination and treatment for horizontal wells with abnormal productivity.

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At present, there are more than 98,000 reservoirs and dams in China. Most of these projects are earth dams. As unexpected disasters and events occur frequently, emergency response problems facing reservoirs and dams are increasingly prominent. Especially during a strong earthquake, the dangerous problems of these dams will be more serious, which is a serious threat to people’s lives and property downstream. Therefore, the seismic damages and the measures of reinforcement need to be studied. Basic data of 379 reservoirs were at high-risk or at dam-break risk, as well as the damage situations of medium and small earth dams damaged in the Wenchuan earthquake, are collected and presented in this paper. Several main failure modes of earth dams during the earthquake are analyzed and summarized. For practical engineering, some reinforcement measures for the typical failure mode of an earth dam are also proposed. The Wenjiajiao earth dam, a typical medium reservoir in the high-risk category, located in Cangxi County, Sichuan Province, is selected as the analysis example. The dam safety and seismic stability are calculated and analyzed by the finite element software program ANSYS. The results indicate that the biggest permanent deformation caused by the earthquake occurred in the dam crest; the maximum deformation is mainly a downward subsidence of 21.8 cm. As the thickness of the dam top part decreases, the dynamic displacement and vibration velocity of the dam crest increases. This calculation is consistent with the actual situation where the parapet wall of a dam crest was seriously incline and the upper slope collapsed and cracked. The research results can provide a reference for the danger control and reinforcement of similar earthquake damaged reservoirs.

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