Solving technical roadbed foundation projects requires strong tamping foundation engineering construction to ensure that the project has sufficient horizontal bearing capacity. Before the construction of the plea with strong ramming foundation to solve the loose fill soil. Requirements tamping energy design program by 4000kn.m, foundation after bearing capacity characteristic value is not less than 155kn/m2.

Strong tamping foundation test tamping test is based on different tamping energy, tamping distance and tamping frequency, in order to seek the design scheme, play the compressive strength of artificial fill, reduce the settlement deformation of the foundation. The design scheme is based on the method of ramming foundation plus artificial fill.

On-site strong tamping foundation project before construction, select the symbol interval to divide the test area, carry out the strong tamping foundation test, through the trial tamping to select the main parameters of engineering construction suitable for local reality, to meet the requirements of engineering construction.

The trial tamping test is carried out on the basis of the structural feasibility analysis of rammed foundations reinforced with rammed foundations artificial filling method. According to the test tamping can distinguish good tamping kinetic energy and tamping number, strong tamping foundation reasonable structural reinforcement deep. The bearing capacity of artificial fill after strong tamping foundation structure reinforcement should be not less than 0.15MPa

In the test tamping experiment, it is generally based on the good tamping energy selected in the experiment, from the falling distance to distinguish the weight of the hammer, or from the deep layer of structural reinforcement to distinguish the lifting capacity of the lifting equipment, as well as the deep layer of the damage caused by the occupancy effect of the good tamping energy.

In a single case, there should be a time interval between the second ramming blows to facilitate the fall of static ground stresses in the soil. After the roadbed soil is firm, it should be tamped again.

When the construction cycle is slow, the soil is leveled after the previous tamping and then tamped continuously without interruption. However, when tamping the backfill, the quality of backfill should be ensured, and good filler should be selected according to the requirements to ensure the construction quality of the project.

Ramming foundation base is a very important part of rammed foundation, the stability of rammed foundation base guarantees the integrity of rammed foundation construction. So ramming foundation base reinforcement is a top priority for construction companies. Ramming foundation method, also called tamping method, refers to the use of a heavy hammer from a high place to free fall tamping foundation, so that the strength of the foundation soil to improve, the compactness is reduced, to eliminate the wet subsidence of loess, so as to achieve the purpose of strong tamping foundation to strengthen the foundation.

With a heavy hammer impact on the soil particles to make it broken or produce relative movement between the water to complete the microstructure damage, but also to make part of the pore space in the rapid contraction or discharge of gas, pore volume decreases, so that it is easy to form a relatively dense soil structure. At present, we divide the reinforcement process of tamping foundation into the following four stages.

(1) Tamping is a process of energy conversion, accompanied by forced contraction or vibration discharge of gas;

(2) Damage to the foundation soil structure or soil liquefaction of the strongly tamped ground, resulting in reduced strength or loss of shear strength;

(3) Foundation ramming foundation reinforcement can accomplish drainage, consolidation and compaction, change permeability, further develop soil fissures and improve soil strength;

(4) Thixotropic restoration allows consolidation and compaction while including a portion of the self-contained water into membrane water, and the strength of the soil continues to improve.