Application Of Reinforcement Technology To High Earth-Rockfill Dam Earthquake-Resistance

The previous research indicated that upper part was failed firstly when earth-rockfill dam was damaged under strongly earthquake loading, rockfill in upper part is under unstable state because of whiplash effect, so, It is necessary to use earthquake-resistant measures to high earth-rockfill dam in earthquake region. Reinforcement anchor technology is a very important retaining method in geotechnical engineering field. It can exploit thoroughly and enhance strength and autostability of rock or soil mass. It has been widely applied in the practical engineering of China because of their advantages, such as material conservation, safety, convenient in construction compared with other retaining methods. In this paper, reinforcement anchor retaining method is numerically analyzed using Lagrange finite difference method to provide some scientific basis for its broad application.At first, a finite difference method is used for the numerically analysis of embankment and earthquake-resistant measures. The reinforced range of dam is validated further by quasi-static method calculation and researching permanent displacement of dam. The performance mechanics of reinforcement and face plate, and the anchorage mode are studied by researching shear strain of dam, accumulating displacement vector, permanent displacement along typical lines, stress and axial force of reinforcement and face plate. Secondly, by studying the effects of the structural parameter of reinforcement and face plate, attentions are paid to the problems, such as different anchor space, anchor length, shoring obliquity, friction angle and cohesive strength between cable and soil, surface thickness. Thirdly, the question about whether changing the soil material parameter of dam without earthquake-resistant measures equivalent to the case with earthquake-resistant measures is studied. Finally, the project is studied by finite difference analysis method and guidance for construction is brought. Some significant conclusions are remarked as follows:(1) It is validated further that the reinforced range of high earth-rockfill dam is 4/5 height upwards. Reinforcing effects highly the distribution and magnitude of the maximum shear strain of dam.(2) The axial forces of reinforcement are all tensile force. As a whole, the tensile forces of reinforcement in the upper are bigger, the tensile force increases form dam slope end to inside end of dam. The axial forces of face plate are the same to anchor, tensile forces, themaximum tensile force is at position of middle reinforcement height and magnitude decreases along the height.(3) Whether permanent displacement of dam or the axial forces of anchor, the rigid attended mode is better than the free attended mode.(4) By studying the effects of the structural parameters of reinforcement and face plate, some qualitative rule is proposed, for example, the anchor should be 1.5 times length than distance between slip crack line and dam slope, and so on.(5) By calculating and analyzing the engineering project, the correctness of mode and feasibility of retaining method using the reinforcement and face plate at dam slope are verified.