Research On The Comprehensive Utilization Of Filledhigh-filling As Building Foundation

When building roads in mountainous areas,most of the gravel produced by blasting is used as embankment filling except for part of it.infill.This kind of high filling body has the characteristics of large filling height,poor compaction,uneven distribution of horizontal and vertical soil layers,etc.If no corresponding measures are taken to deal with it,it will face excessive settlement difference and insufficient foundation bearing capacity,etc.shortcoming.Correspondingly,compared to "cutting peaks and filling valleys" in mountainous areas and re-filling high fill bodies with a height of more than 20 m,this kind of high fill fill bodies can be used as building foundations only after foundation treatment,with strong strength.High,fast construction,low cost and short cycle.Therefore,the treatment of high-fill building foundations is also very important.Taking a resettlement housing project in Tongren Mountains,Guizhou as an example,this paper studies the reprocessing method of high fill as the building foundation.The main research contents include the following aspects:(1)Investigation and analysis of on-site engineering geological conditions.Due to the complex engineering conditions on site,the engineering properties of high fill should be clarified first.During drilling,it is difficult to drill and prone to collapse,so the site is surveyed by a combination of surface waves and drilling.The foundation is layered by surface wave,and then the method of drilling is used to verify the correctness of layering and determine the filling material.The results show that the filled foundation is mainly composed of blasted crushed rock,mixed with a small amount of cohesive soil and large crushed rock.(2)Experimental study on physical and mechanical properties of weak body with high fill on site.Through indoor and outdoor experiments such as particle analysis,heavy-duty compaction,and plate testing,the properties of the foundation fill and the calculation parameters of the fill are determined.The deformation modulus is 6.0MPa,and the compaction degree is 80.0%,indicating that the engineering properties of the weak body are very poor,and it is not suitable to be used directly as a building foundation,and foundation treatment is required.(3)Settlement calculation of high fill foundation soil.Adopt the method recommended in "Technical Specification for Building Foundation Treatment" Code for the Design of Building Foundations(GB 50007-2011)to calculate the settlement of the proposed building without foundation treatment.The settlement calculation includes two parts: settlement under additional stress and post-construction settlement.It shows that the uneven settlement without foundation treatment is up to 56 mm,which does not meet the requirements of uneven settlement in " Code for the Design of Building Foundations(GB 50007-2011).Combined with the actual engineering situation,the foundation treatment method is to replace the fill.Cell room reinforced cushion.(4)Research on the treatment method of high fill foundation soil.The field test and numerical simulation of the geocell reinforced cushion are carried out.The experimental results show that the failure of the geocell reinforcement generally starts from the connection point,The numerical simulation results show that the geocell reinforcement can effectively improve the bearing capacity of the foundation and reduce the settlement of the foundation.The higher the height of the cell,the smaller the size of the single cell,the better the reinforcement effect of the cell.The elastic modulus of the geocell reinforced cushion increases proportionally with the change of the filling modulus。(5)Check calculation and settlement prediction of uneven settlement after foundation treatment.The settlement check of the building after foundation treatment is carried out,and the factors affecting the reinforcement effect of the geocell are quality-controlled through field tests.Combined with post-construction settlement monitoring data,the settlement is analyzed.The results show that the uneven settlement after foundation treatment meets the requirements of " Code for the Design of Building Foundations(GB 50007-2011),which is 40%-69% lower than that before treatment.Under the condition that the quality control of the geocell is qualified,the geocell can reduce the settlement of the top surface of the foundation by 18%.The post-construction settlement is also predicted,and the exponential function model can fit the settlement more appropriately,which provides a reference for similar projects.