Analysis Of Failure Modes Bearing Capacity And Stability Of Strip Foundations Adjacent To The Slopes

In engineering practice,due to engineering needs and terrain conditions,the foundation of buildings and structures is inevitably placed near the foundation pit or at the top of the slope.Such foundations are called foundations adjacent to the slopes.So far,there is no reasonable systematic explanation for the bearing problem of the foundations adjacent to the slopes.The main problem is that when the slope top is subjected to the engineering load,it is necessary to consider the interaction between the foundation bearing and the slope stability at the same time,which becomes more complicated.At present,the research on the bearing capacity of the Strip Shallow Foundations Adjacent to the Slopes mainly focuses on a single saturated clay??=0°?and sandy soil?c=0kPa?,However,there are few studies on the common c-?type soil in engineering practice.In the existing research,the failure mechanism based on classical horizontal foundation is used to analyze the bearing capacity of the failure mechanism of the foundations adjacent to the slopes.The understanding of the failure mechanism of the foundations adjacent to the slopes involving both bearing capacity and slope stability is still unclear.There is no reasonable comprehensive consideration of carrying capacity and stability for the safety assessment of the foundations adjacent to the slopes.Based on the predecessors,this paper analyzes the change of failure mode transition and ultimate bearing capacity of the sloped soil under different conditions,and proposes the method of determining the failure mode of the slope on the slope.The safety degree of the foundation is carried out from two aspects:bearing capacity and slope stability.Evaluation.The main contents and conclusions are as follows:1?The finite element method is applied to the modeling of the foundations adjacent to the slopes,and the comprehensive influence of bearing capacity and slope stability on the bearing capacity of the foundations adjacent to the slopes is analyzed.Three types of bearing failure mode,bearing-stability coupling failure mode and slope instability failure mode are proposed based on the failure mechanism.The refinement is Prandtl-type failure mode,the bearing failure of the slope foundation mode,face bearing failure mode,toe bearing mode,toe failure mode,and the stability of the slope mode according to the distribution form and development process of the failure surface,and the basis for determining the failure mode of foundations adjacent to the slopes is established.2?The relationship between the failure mode of the slope and the ultimate bearing capacity and its influencing factors are studied.When the failure mode is face bearing failure mode,the ultimate bearing capacity increases linearly with the increase of cohesion with c,and increases with the gradient?,which does not change with the slope height H/B,with the load position?.When the failure mode is bearing-stability coupling failure,the ultimate bearing capacity increases nonlinearly with the increase of cohesion with c,and increases with the gradient?,which does not change with the slope height H/B.The change increases first and then decreases with the load position?.3?The analysis of the transformation law between the failure modes of the slope on the slope and the determination method of the failure mode are proposed.There is a limit distance?_cr.When?>?_cr,the sloped foundation is no longer affected by the slope,and Prandtl-type failure mode occurs.When H/B<1.5,the failure surface extends below the foundation surface,and the bearing failure of the slope foundation mode occurs.When the slope stability is low,the soil's own weight has a negative impact on the ultimate bearing capacity of the sloped foundation?N?<0?,bearing-stability coupling failure mode occurs;when the slope's own stability is close to the limit state,the slope-based foundation failure surface Unaffected by the ultimate load,the slope is unstable.4?For the horizontal foundation and the sloped foundation,the relationship between the bearing safety factor K and the stability safety factor F_s and its influencing factors are studied.The stability of the foundation under the load of the bearing capaci ty is analyzed.When using the?Building Foundation Design Code??GB50007-2011?to design the bearing capacity of the foundation,the horizontal foundation stability safety factor F_s>1.25meets the stability requirements,and the slope safety factor F_s increases with the height H and the slope rate becomes steeper.The load position?becomes larger and decreases.There is a safety distance?_sa.When?>?_sa,the stability safety factor F_s>1.25 of the slope-based foundation under the bearing capacity load is not affected by the slope.