Along the expressway, there are 4 provincial and municipal water source protection areas and forest protection areas, as well as many mines left over from historical mining, which is a problem encountered in the construction of Yunnan Sanqing Expressway project.

Before the project is started, the builders has encountered technical problems. The traditional impact drilling construction will affect the stability of geological structure, and it is easy to pollute water source in the process of pouring concrete on pile foundation. The pouring of cement slurry during the construction of the bridge will also pollute the water flow under the bridge, which will lead to the pollution of the water source protection area.

The project leader and technicians worked together to optimize the construction plan, and finally got a set of "minimally invasive treatment" construction method with multiple benefits. That is, while completing the construction task, we should do our best to protect the water source and forest reserve, and restore the damaged mountain appearance of the mine pit.

In pile foundation construction, the project uses rotary digging into the hole construction, through the "minimally invasive" way, in the construction area to open a "minimally invasive opening", with concrete pouring pile foundation to restore the mine; During the construction of the bridge deck, culvert pipes are set up to ensure the circulation of water sources under the bridge. After the completion of the construction, measures such as expansion, dredging, setting up dregs blocking facilities and vegetation greening are taken to effectively ensure that the water sources are not polluted.

The project takes full advantage of the pits along the construction line as the abandoned soil field, and sows grass seeds after the pits are filled for reclamation and greening. Up to now, the project has completed 3 large pits and more than 10 small pits, restoring arable land of nearly 30 mu, protecting the environment while also increasing land resources!

The Qujing section of Sanqing Expressway was officially completed and opened to traffic, which greatly alleviated the traffic congestion of Kunqu Expressway and promoted the fast connection between Qujing city and southeast area of Kunming city and central Yunnan City economic circle.