| According to the development plan of China Civil Aviation,China airport construction will develop rapidly.For example,by the end of 13th Five-Year,the number of airports in China will reach 260,an increase of 62 over 2016,an average annual increase of 13 airports.But now,due to a shortage of land for the city,airports are mostly built in the area of poor geological conditions,such as coastal or reclamation of soft soil,the high embankment of mountainous or hilly areas.In such geological conditions,the settlement control of subgrade has become the key to the success of the project.After many airports are put into use,the road surface produce excessive settlement,even resulting in a large area of pavement damage,to bring a huge risk to the safe and efficient operation of the airport.If the road surface is repaired or reconstructed,it will cause economic losses and social influence.Therefore,how to carry out non-stop flight to repair the settlement of road surface,restore its smoothness and improve its bearing capacity,is an important problem to be solved urgently in the field of Civil Aviation Airport.Based on the above background,the main research contents and results are as follows:1.A new type of geopolymer resin which is newly introduced in the field of construction is chosen as the material for airport pavement,and its physical and mechanical properties are studied.First of all,the material expansion performance testing and specimen forming mold is manufactured.Then,in the process of polymer resin filling molding,the expansion force is tested under different density conditions.Finally,the mechanical properties of different density of polymer resin specimens are tested on the universal testing machine.The experimental results show that compared with the traditional polymer resin,the new type of polymeric resin has higher swelling power of 1.5%under the same density condition,the elastic modulus is higher than 13.8%,and the compressive strength is higher than 25%.The above parameters provide the basic parameters for subsequent research.2.When the polymer resin is used to process the pavement,the improvement of the pavement bearing capacity is mainly affected by the parameters such as the stiffness size and the uniformity of the grouting solid.For the same kind of geopolymer resin,the compressive modulus and strength index are directly related to the density of the solid.And under the same conditions of temperature and material filling rate,the density of the solidified body depends on the restraint of the material when expending.Therefore,to obtain the density of solidified body by the theoretical analysis is one of the key technologies to deal with the polymer resin when pavements are treated by polymers under different deformation conditions,different parts and other conditions.The finite element method is used to analyze the binding force variation law of the resin expansion under the condition of different pavement structures parameters and three kinds of grouting positions in the edge of the plate,the plate and the plate angle.Then,the constraint solving equation is established.Combined with the actual case,the results show that when grouting at the corner of the plate,the lifting amount is 4 mm,the density of the polymer is 0.3728 g/cm~3,and the elastic modulus of the polymer is 166 Mpa.When grouting at the middle of the plate,the lifting amount is 1.7 mm,the density of the polymer is 0.25 g/cm~3,and the elastic modulus of the polymer is 106 Mpa.When grouting at the edge of the plate,the lifting amount is 3.2 mm,the density of the polymer is 0.315 g/cm~3,and the elastic modulus of the polymer is 138 Mpa.3.Based on the above two aspects,the improvement of the pavement bearing capacity is studied by the finite element method.The finite element method is used to analyze the influence of settlement and settlement range on the additional stress of airport sinking pavement.In a certain range of settlement,according to the different settlement,sinking pavement is filled with polymer to reinforce.According to the different conditions and light,medium and heavy aircraft load,a large number of calculations are proceeded.The results show that,when the settlement of the airport pavement reaches 5 cm,the pavement can not meet the needs of normal taking off and landing for heavy aircraft.With the increase of differential settlement,the airport pavement can not meet the requirements of normal taking off and landing for medium aircraft.And when the differential settlement reached 10cm,light and other aircraft can not take off and land normally.After the consolidation of polymer grouting,the structural capacity of the airport pavement structure is significantly improved,which can meet the requirements of the normal taking off and landing for kinds of aircrafts.And when the differential settlement is less than 5 cm,the bearing capacity of airport pavement can be recovered to about 74%~84%of the design value through grouting. |
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