Xing Le

(Zhengzhou Municipal Engineering Quality Supervision Professional Station,Zhengzhou,Henan 450000)

Abstract：In recent years,with the rapid development of science and technology,municipal engineering in China has made some remarkable achievements.However,problems also follow,such as during the process of municipal engineering construction,many bad foundations were encountered;due to the social and economic progress,as well as the increase of foundation structure load,the requirements of municipal engineering to the foundation are getting much stricter.Foundation is the carrier of the basic construction,and also the ultimate load bearing of some engineering structures,although it is not an integral part of engineering structures,it plays an indispensable role in municipal engineering.Moreover,as the upper load of the supporting engineering structure,the foundation is closely related to the safety of the engineering structure itself,so higher requirements are put forward to the foundation.The requirements are as follows:The overall stability of engineering structures should be reliable;the bearing capacity of the foundation should be adequate;as the load action of engineering structures,the foundation will produce horizontal displacement,and some unbalanced settlement should meet certain numerical requirements.

Keywords：municipal engineering;foundation detection;key technology

As the ultimate load bearing of some engineering structures,although the foundation is not an integral part of the structure itself,it plays an indispensable role in the completion of municipal works.On the one hand,this paper discusses the importance of foundation detection of municipal engineering;on the other hand,it discusses the key technologies in the process of foundation testing of municipal engineering,hoping to provide some practical theoretical help to the relevant researchers in the future.

I.Review of Foundation Detection of Municipal Engineering

(i) Definition of Foundation Detection of Municipal Engineering

Generally speaking,there are two kinds of foundation detection,natural foundation detection work and some composite municipal engineering detection works[1].Composite foundation detection work refers to the careful inspection of some special environments.During the inspection process,the staff focuses on controlling the bearing capacity of the foundation,which can be controlled by punching pile,root pile and other methods.The work and operation of natural foundation detection work is simple,which is mainly to test the bearing capacity and stability of foundation.

(ii) Importance of Foundation Detection of Municipal Engineering

The result of foundation detection of municipal engineering will directly affect the quality of the whole foundation engineering,at the same time,through the inspection,the construction personnel can find out the problems in the construction process at the first time,and implement remedial measures in time,so that the project can be completed smoothly[2].On the other hand,in our real life,most construction companies need to implement the improvement of various problems according to the foundation inspection,in this way,it can guarantee the quality of foundation works in municipal engineering,promoting the economic development of the company and bringing more profits to the company.Therefore,it is very necessary to study foundation inspection.

II. Key Technology of Foundation Detectionof Municipal Engineering

As the first step of the engineering construction,the foundation plays an important role in municipal engineering construction.That is,if the foundation has sufficient stability and bearing capacity,then the overall safety of engineering structures will be guaranteed,preventing the occurrence of many adverse circumstances,so it is necessary to pay attention to the foundation construction.In the process of foundation construction,the first requirement should be satisfied,which is to have a huge bearing capacity,to ensure that there is no danger in the subsequent high-rise building.

(i) Settlement Value of Engineering Structure and Allowable Deformation Value of Foundation

In the process of municipal engineering construction,we should give full consideration to the foundation construction,not only the bearing capacity of the foundation should be considered,but also should we think scientifically about the strength and stiffness of the engineering structure to be built later,so as to be able to handle various emergencies with ease.When different deformation values are generated,the engineering structure itself will not be adversely affected under any circumstances[3].In addition,we should also consider the using approaches of some engineering structures.For some engineering structures with different uses,we should adopt different deformation values,that is,to effectively control the deformation value[4].For example,for those foundation whose geology is relatively uniform and its load force is equally distributed,we can use the numerical value generated by foundation settlement to control the deformation value,that is,to control it by adopting relatively curved control values,and reasonably evaluate the ratio which generated by the vector height of the curved part and its overall length[5].Moreover,for those special engineering structures with locally different settlement,we can choose to calculate the ratio of settlement difference and the distance between two points,that is,the local inclination value,and then check.Similarly,we may encounter simple engineering structures such as industrial plants on the construction site in the municipal engineering construction site.In most cases,the detection and control are determined by the required allowable deformation value.

(ii) Bearing Capacity of Foundation

We should take full account of the bearing capacity of the foundation,which refers to the guarantee for the completion of subsequent engineering structures and the safety of the completed engineering structures,therefore,the bearing capacity of the foundation also becomes the key to ensure the safety of the building,so we must give full consideration to the calculation of the bearing capacity of the foundation when construct the foundation,and make the pressure per unit area under the foundation is not greater than the bearing capacity of the foundation.

III.Related Treatment Methods of Foundation Detection of Municipal Engineering

Foundation consolidation principle, which means to make the moisture content of soil from high to low.In order to make the moisture content from high to low,it is necessary to make the soil quality in the foundation from loose to solid[6].Therefore,in order to achieve the purpose of strengthening the foundation,we commonly use three manual treatment methods,compaction method,soil replacement method and pile driving method,to achieve the purpose of consolidating.The foundation is the carrier of the basic construction,is the ultimate load bearing of some engineering structures,it plays an indispensable role in the completion of municipal engineering,so it is imperative to consolidate the foundation.When consolidating the foundation,we need to combine the above structure of the building in the municipal engineering and the geographical position and the soil condition to confirm the reinforcement measures.

(i) Compaction Method

Compaction method,which means to use a roller or a heavy hammer to grind,squeeze out the thin air between particles in the underground soil layer,so as to improve the density between particles in the soil and achieve the purpose of increasing the bearing capacity[7].The advantage of compaction method is that it is easier to operate.This method is generally suitable for situations where the design requirements are similar to the carrying capacity.

(ii) Soil Replacement Method

Soil replacement method,which means to remove the soil with poor bearing capacity at the bottom of the foundation,then replaced by ash or sand with high bearing capacity and density,and use layered backfill method[8].The backfill materials can be ash,sand,etc.Sand foundation is easy to operate and economical,it not only needs a short time period,but the cost is also low,it is suitable for those cohesive foundation with strong permeability.

(iii) Pile Driving Method

Pile driving method refers to the method of driving piles into soil layers with low bearing capacity to further improve soil density and indirectly improve soil bearing capacity[9].We will briefly describe a commercial and residential structural engineering pile construction case hereinafter.First of all,what we need to do is to establish reference points and set protection marks on the site according to the provided general layout plan of commercial and residential structure.In the foundation treatment,that is,when we start to carry out the palification,the specific operations are as follows:firstly,insert the pile tip into the pile position,and the vertical deviation degree of the pile shall be controlled within 0.5%.When we start palification,a heavy hammer with lightly blow should be used,and the palification should be done continuously,during the construction of pile sinking,the construction personnel should record the hammer strokes per meter sunk,and then pick up the pile,and finally send the pile.

IV.Conclusion

As the name implies,foundation is a rock mass or soil mass supporting the whole building under the building object.The foundation is a relatively hidden work,while its quality is the guarantee of the quality of the building.In the process of municipal engineering construction,the foundation construction is the most important link,and also the one should be paid special attention,which has a great impact on the quality safety of engineering structures afterwards.Without foundation inspections or perfunctory inspections,it will be too late to inspect the work until it is completed,and the hazards are difficult to detect.If something goes wrong,it will be hard to fix it,and even harder to imagine the consequences.Therefore,the quality inspection,survey,design and construction of foundation are extremely important parts of the overall construction project,and are also the top priority of the project.Great attention must be paid to ensure that the testing and monitoring technologies of foundation are qualified and promote the healthy and sustainable development of the construction industry.On the other hand,due to the rich land resources in China,the uneven land conditions are created,so we should adopt different foundation testing technologies in the process of municipal engineering foundation testing.We should consider the soil condition scientifically,optimize the foundation inspection work in municipal engineering as much as possible,and guarantee the quality of municipal engineering.