| This paper analyzes the law of deformation and destruction on the basis of the friction conditions and the crest of the slope foundation bearing capacity, based on centrifugal model test of sloping ground. Considering the influence of parameters of foundation soil, slope conditions, loading conditions and the friction condition on the limit curve and peak load, linking with the change of plastic zone in the body, the internal mechanism is analyzed. The main research results are:1. The damage form of the slope foundation is asymmetry, under the limit load, in the foundation to the slope side slip, slip crack surface intersection on the slope surface part. Comparing with the ground foundation, the foundation based on the slope are more likely to incline, which may lead to the basis for significant state of slope displacement, and come to the ultimate bearing capacity. Basic location affect the slope deformation and destruction of the form; When the slope distance is more than 4 times of the based width, the deformation and failure law is approach to ground foundation; The friction conditions of basis will affect the size of the foundation bearing capacity and failure surface form.2. Using the top load condition, the differential calculation program is written, which can calculate the active area, transition area and passive area of each calculation point x, y, and values under the limit equilibrium state, and ultimately determine the limit curve of the slope under known load. The results show that the limit slope curve slope decreased with the increase of y smaller. Due to the existence of the basal friction, active area AOB turns into asymmetric triangle, the open Angle ?AOB decreased. Transition area and passive area is shifted to the internal zone of soil, and limit slope curve is decreased obviously. The increase of peak load resulting in limit slope rate slow, slope foot down, and moving outward. The increase of soil heavy causes extreme move outward of limit slope curve, slope foot down. Caused by the increase of soil strength parameters, transition region open Angle ?BOC diminished, slope curve reduced, and slope rate enlarged; the increase of cohesive force will also cause the transition area and passive area’s reduction.3. The top of slope ultimate load increases with the increase of x value, its growth rate with increasing x value becomes smaller, the results are consistent with the ground foundation. Basal friction conditions on the inside of the plastic zone sloping ground. The greater friction coefficient as tan ?, the soil in the transition area increases, the active area narrowed. The top of slope ultimate load growth rate increased rapidly with the increase of tan ?.4. The top of slope ultimate load value and its growth rate with increasing slope rate increases. Changes in slope height H has no significant effect on top of the slope the ultimate load. Increased range caused severe soil in plastic zone increases, causing an increase in ultimate load crest. Weight of Soil O point has no effect on the crest of the ultimate load. Increase the cohesion of the soil makes the range of plastic zone extends to the internal earth, causing an increase in the load of a hill, on top of the hill but the growth rate has little effect on the ultimate load. Increased internal friction angle of the soil makes plastic zone is narrowing, but a greater impact on a hill load growth.5. For consideration of principal stress effect on the slope of foundation, the unified strength theory is introduced to establish the unified slip line equation of slope foundation, and its decomposition, in principal stress is studied on the bearing capacity of the foundation slope destruction form and influence.With the increase in the principal stress effect, limiting slope curve slope increases. Toe ordinateDy with b values follow the rules of the first increases and then decreases. As xample 1, when b=0.4 and b=1.0, the ultimate bearing capacity at point O increases 25.58% and 61.18% compared with b=0. |
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