In the construction of construction projects, dynamic compaction method as a common foundation reinforcement method, in essence, is to strengthen the foundation, make the soil compact, improve the soil bearing capacity, so as to provide a stable guarantee for the future construction. Therefore, the quality inspection of dynamic compaction is very important.

一、机器设备

1、 Machinery and equipment

1,夯锤

1. Rammer

夯锤可分为整体夯和组合夯两种类型:整体夯和组合夯;由钢板制成。夯锤一般选用较圆的锤印，因为圆锤印很容易重合。锤底面积大小取决于土壤表面:砂土一般为3~4m2;粘性土应小于6m2。锤重一般为8、10、12、16、25、30t等。在锤击过程中，锤头和锤底常布置若干直径为60~200mm的通风孔排出，以减少锤击时的吸力。

Rammers can be divided into two types: integral rammer and combined rammer, which are made of steel plate. Rammers generally use round hammer marks because they are easy to overlap. The hammer bottom area depends on the soil surface: sandy soil is generally 3 ~ 4m2; cohesive soil should be less than 6m2. The hammer weight is generally 8, 10, 12, 16, 25, 30t, etc. In the process of hammering, a number of ventilation holes with diameter of 60 ~ 200 mm are arranged at the hammer head and hammer bottom to reduce the suction during hammering.

2. 起重设备

2. Lifting equipment

a、一般选用履带式起重机或其他起重设备(如专用三脚架、龙门架等)，起重能力为15、30、50t。提升设备的升降高度必须满足动态夯锤的要求。选择主动钩锤设备，起吊能力应大于锤重的1.5倍。

a. Generally, crawler crane or other lifting equipment (such as special tripod, gantry, etc.) is selected, with lifting capacity of 15, 30 and 50 t. The lifting height of lifting equipment must meet the requirements of dynamic rammer. Choose the active hook hammer equipment, the lifting capacity should be greater than 1.5 times of the hammer weight.

B.解耦装置应具有所需的强度和灵敏度，以保证每台夯锤的射击距离相同。

B. The decoupling device shall have the required strength and sensitivity to ensure that the shooting distance of each rammer is the same.

c、当吊车起升能力不足时，可采用在吊杆上加装支撑杆，增加起升能力。

c. When the lifting capacity of the crane is insufficient, the support rod can be installed on the suspender to increase the lifting capacity.

二、施工过程质量检查

2、 Key points of quality inspection in construction process

1. 视图的内容

1. Content of view

锤重、落锤距离、夯点位置、夯击次数和夯击次数之间的间隔。

Hammer weight, drop hammer distance, location of tamping point, tamping times and spacing between tamping times.

2. 质量控制

2. Quality control

a、施工前，根据锤重、落差、夯点布置、夯点个数等规划要求，进行现场夯试验，确定正式施工中使用的技术参数。

a. Before construction, according to the planning requirements of hammer weight, drop, tamping point layout and number of tamping points, on-site compaction test is carried out to determine the technical parameters used in formal construction.

b、强夯基础场地按预先定好的地面标高，用推土机进行平整。地面时细土,地下水位高,表层应铺约0.5 ~ 2米的砂、碎石或砂砾,以形成一个硬层表面上,避免设备抑郁和容易消散孔隙水压力的动态压实,并能增加地下水和外表面之间的间隔,以避免捣固功率下降。当局部较低水位低于地表2m且地表为非饱和土时，可直接进行夯实。

b. The dynamic compaction foundation site shall be leveled with bulldozer according to the pre-determined ground elevation. When the ground is fine soil and the underground water level is high, the surface layer should be paved with 0.5 ~ 2m sand, gravel or gravel to form a hard layer on the surface to avoid equipment depression and dynamic compaction which is easy to dissipate pore water pressure, and can increase the interval between groundwater and external surface to avoid the reduction of tamping power. When the local low water level is 2m lower than the surface and the surface is unsaturated soil, it can be directly compacted.