Interaction Analysis Of Rock Slope Subgrade With Superstructure And Foundation

With the development of western region in China,many buildings have to be situated on slope subgrade. Interaction of rock slope subgrade with superstructure and foundation become a realistic and important research project in geotechnique practice. By the use of theoretic method and numerical simulation, the dissertation studied this subject on the base of the previous relative works adequately. Corresponding main work and achievements are as follows:â‘ Point to the influence of foundation types to interaction of superstructure and foundation with rock slope subgrade, investigation was carried out. Analysis results show that pile foundation is the best type for improve safety degree of slope and reduce the displacement and additive internal force influence of superstructure. If it is necessary to use shallow foundation types (single expanded foundation, strip foundation, raft foundation), continuous foundation types (strip foundation or raft foundation) should be taken in use preferentially. Numerical analysis conclusion can be a useful reference to engineering practice.â‘¡Point to the influence of slope to interaction of superstructure and foundation with rock slope subgrade, investigation was carried out and that include different rock mass strength, slope gradient and slope height. Corresponding main results are as follows:1) When slope rock mass strength is high, horizontal and vertical displacement of the slope and superstructure will be small at the same time, settlement in every point of the foundation and the difference between these settlement and moment internal force in foundation can be reduced at the same time. Rock strength has important influence to superstructure internal force, especially to the internal force of column in ground floor. If rock strength is low, the additive internal force influence in the superstructure will be high.2) When slope gradient is big, slope and superstructure will lean toward the slope incline surface. When slope gradient is small, the corresponding result will be adverse. Small slope gradient can obtain small slope displacement, high slope safety degree and small foundation average settlement. To the foundation part which near the slope incline surface, small slope gradient will cause high internal force at the foundation point which under the column base and internal force at the foundation point which between the columns will be reduced. With the slope gradient become small, moment in superstructure become more symmetrical, but moment value of the side column in ground floor will become larger when compared with rigid subgrade circumstance, especially to the base of column in ground floor.3) When slope height is high, horizontal and vertical displacement of the slope and superstructure will be large and slope will obtain large plastic zone, settlement in every point of the foundation and the difference between these settlements will become larger at the same time. Influence of slope height to foundation moment internal force is relatively high to moment internal force in the foundation part which near to slope incline surface. To the foundation part which near the slope incline surface, high slope height will cause high internal force at the foundation point which under the column base and internal force at the foundation point which between the columns will be reduced. Slope height directly caused moment in middle column of ground floor will be produced and its bottom value will larger than top value. Additionally with the higher of the slope height, moment value of the side column in ground floor will become larger when compared with rigid subgrade circumstance, especially to the base of column in ground floor.â‘¢Point to the influence of superstructure to interaction of superstructure and foundation with rock slope subgrade, investigation was carried out and that include different building distance and building stories. Corresponding main results are as follows:1) Large building distance is helpful to reduce horizontal displacement in slope and superstructure, reduce average settlement of raft foundation, and ensure the safety of slope and superstructure. When building distance is small, the raft settlement curve will lean toward the slope incline surface. When building distance is small, the corresponding result will be adverse. Influence of building distance to foundation moment internal force is not obvious and only has effect to moment internal force in the foundation part which near to slope incline surface. To the foundation part which near the slope incline surface, large building distance will cause high internal force at the foundation point which under the column base and internal force at the foundation point which between the columns will be reduced. With the increase of building distance, moment in middle column of ground floor in superstructure will decrease, but moment value of the side column in ground floor will become larger when compared with rigid subgrade circumstance. 2) Few building stories are helpful to reduce horizontal displacement in slope and superstructure, ensure the safety of slope, and settlement curve of raft foundation will become relatively smooth. Change of building stories will cause obvious influence to superstructure and foundation. With the increase of stories, whatever at the base of column or between columns, internal force of raft foundation will be increased at the same time, and asymmetry trend of the internal force distributing will be strengthened and the moment in the foundation part near the slope incline surface will larger than the part far from the slope incline surface. Reduce building stories, internal force of superstructure becomes more symmetrical (internal force of middle column become lower). But when increase building stories, internal force distribution of column in ground floor will become reverse, especially to the base of side column in ground floor which near the slope incline surface. Some results above can be a useful reference for engineering design.â‘£C++ language is used for devise of rock slope subgrade, superstructure and foundation interaction analysis program RSFIAP-2008. With the program, numerical computation analysis for the interaction of multilayer frame structure and single expanded foundation, strip foundation, raft foundation, pile foundation with homogeneous rock slope subgrade can be carried out. Corresponding analysis results are helpful to science research and engineering practice.