1. Before dynamic compaction, the site soil layer needs to be stabilized and consolidated

适用的强夯法回填土场地需行自然堆载预压，自然预压堆载时间，堆载时间要让土层稳定，处于淤泥质土、淤泥和冲填土等饱和粘性土等要设塑料排水带砂井等排水竖井，总之在进行强夯或者强夯置换前要使场地的土层达到自然固结或者预压固结。

For the applicable dynamic compaction method, natural preloading should be carried out at the backfill site. The natural preloading time and stacking time should make the soil layer stable. The plastic drainage belt sand well and other drainage shafts should be set up in the saturated clay soil such as muddy soil, silt and flushing fill. In short, the soil layer of the site should be naturally consolidated or preloaded before dynamic compaction or replacement.

2、适用范围：

2. Scope of application:

强夯法适用处理碎石土、砂土、低饱和度的粉土和粘性土、湿陷性黄土、素填土和杂填土等；强夯置换法可适用高度饱和的粉土与软塑~流塑的粘性土等对地基变形控制不严格的工程。

The dynamic compaction method is suitable for the treatment of gravel soil, sandy soil, silt and cohesive soil with low saturation, collapsible loess, plain fill and miscellaneous fill, etc.; the dynamic compaction replacement method can be applied to the projects with high saturation silt and soft plastic ~ flowing plastic cohesive soil, which do not strictly control the foundation deformation.

3、试夯确定地基承载力、参数、场地高程：

3. The foundation bearing capacity, parameters and site elevation are determined by trial compaction

地基强夯处理施工前，应根据施工现场有代表性的场地选取一个或几个试验区，进行试夯或试验性施工。试夯后记录试验参数，夯点的累击次数，累计沉降量，两击平均沉降量应满足设计要求，强夯结束后一周数周，要进行地基承载力检测，以判定强夯设计、施工方案是否满足设计承载力要求，试夯后也可确定累计沉降量，可以预估试夯后场地的水平高程、场地是否需要补土或者削土。

Before the foundation dynamic compaction treatment construction, one or several test areas should be selected according to the representative site of the construction site for trial compaction or experimental construction. After the trial compaction, the test parameters, the cumulative number of tamping points, the accumulated settlement and the average settlement of two hammers shall meet the design requirements. After one week to several weeks after the dynamic compaction, the foundation bearing capacity shall be tested to determine whether the dynamic compaction design and construction scheme meet the design bearing capacity requirements. After the trial compaction, the accumulated settlement can also be determined, and the horizontal elevation and site of the site can be estimated No need to add soil or cut soil.

4、大面积施工前场地条件：

4. Site conditions before large area construction:

施工前场地要进行平整，场地表面如果有巨大的孤石要先，曾遇到一个工程，强夯场地表面有很多花岗岩巨石，工程技术人员都比较头痛，决定试夯后表面孤石并整平场地；试夯后确定是否需要补土或者削土，使整个场地强夯后的地面高程能达到设计要求，以免强夯后地面标高偏高或者偏低，偏高则需削土，偏低则需回填土或再做地基处理，两者皆造成建设成本增加和施工工期的延长。

Before construction, the site should be leveled. If there are huge boulders on the surface of the site, it should be removed first. Once upon a project, there were many granite boulders on the surface of the dynamic compaction site, so the engineering and technical personnel had a headache. They decided to remove the boulders on the surface and level the site after the trial compaction. After the trial compaction, we determined whether it was necessary to add soil or cut soil, so that the ground elevation of the whole site after dynamic compaction could meet the design requirements In order to avoid high or low ground elevation after dynamic compaction, soil cutting is required for high ground elevation, and backfill or foundation treatment is required for low ground elevation, both of which will increase construction cost and prolong construction period.

5、场地地表下是否有地下水：

5. Whether there is groundwater under the surface of the site:

如果强夯场地地表下有地下水，强夯过程需要有排放地下水的措施，如挖集水坑、排水

If there is underground water under the ground surface of dynamic compaction site, the measures of discharging groundwater are needed during dynamic compaction, such as digging sump and drainage

沟等进行抽水排水；如果没有排除地表下的地下水，强夯过程，土体中的空隙水将无法被挤压排出、土体的空隙率将很高、密实度差，场地经强夯后无法达到设计要求。

If the groundwater under the surface is not drained, the void water in the soil will not be squeezed out, the void ratio of the soil will be very high and the compactness will be poor, and the site can not meet the design requirements after dynamic compaction.

6、排查场地周边建筑物、地下管线情况，是否设置隔震沟：

6. Check the conditions of buildings and underground pipelines around the site, and whether isolation ditch is set up

由于强夯对地面的挤压作用比较大，所以必须排查强夯区域场地周边建筑物、地下管线、市政设施情况，以面强夯破坏现有建筑物基础、地下管线和市政设施，如果有上述构筑物等，则应设置隔震沟，由于设计规范和施工规范没有涉及强夯隔震沟如何设置的内容，我们依据以往工程实践经验认为隔震沟的深度宜为强夯影响深度的0.7倍以上或者宜现场试验决定，隔震沟的开挖需符合土方放坡稳定要求。

Due to the large squeezing effect of dynamic compaction on the ground, it is necessary to investigate the surrounding buildings, underground pipelines and municipal facilities in the dynamic compaction area, and destroy the existing building foundation, underground pipelines and municipal facilities by surface dynamic compaction. If there are the above-mentioned structures, the isolation ditch should be set up. Since the design specifications and construction specifications do not involve how to set the dynamic compaction isolation ditch, Based on the previous engineering practice experience, we think that the depth of the isolation ditch should be more than 0.7 times of the depth affected by dynamic compaction, or it should be determined by field test. The excavation of the isolation ditch should meet the requirements of earthwork slope stability.