Trenchless technologies

Smart replacement of wells and pipes with modular shoring system

     We would like to present you the method used by us and our customers to replace old wells and pipes with minimal environmental disruption. To show you all the stages of this process, we have created a 3D animation illustrating the entire process step-by-step: from the demolition of the old well to the installation of the new one.

The process of well and pipeline replacement can be divided into three stages:

 I - dismantling of the old well
 II - carrying out works in the shoring system (e.g.. installation of a new pipe, pipe bursting, lining
 III - installation of a new well and restoration of the surface



Stage I - Dismantling of the old well inside the shoring system.

What are the advantages of using the modular shoring system?

  -  limiting the size of the excavation and minimizing the disruption in the environment;
  -  ensuring a safe and ergonomic working space inside the excavation;
  -  protection of persons and equipment from soil slippage at tepths of up to 5 m.

     Furthermore, the shoring system is equipped with a ladder, shelves and slots for mounting hydraulic equipment, such as MNB-50 and MNBL-70, machines, and a set of hydraulic lifting cylinders used for lifting the shoring from the ground after the work is done.

  Fig. 1. Modular shoring in an excavation 

Fig. 2. Mounting of MNB-50 in the modular shoring

    
 Fig. 1. Modular shoring in an excavation Fig. 2. Mounting of MNB-50 in the modular shoring      



Stage II - carrying out works in the shoring system:
pipe repair, maintenance or replacement, installation of laterals etc.


     A bursting head is used to crack open and replace the old pipe. The bursting head presented in this animation allows water flow through the pipe during the pipe bursting process.

     If the new pipe consists of modular sections, we use a hydraulic tightening device. The pipe modules are tightened with a chain, and the tensioning force is regulated with a manual pump equipped with a manometer. This silution is used to prevent the pipe section from disconnecting during the bursting and pulling.

  Fig. 3. Tightening device 

Fig. 4. Flow-through bursting head

    
 Fig. 3. Tightening device Fig. 4. Flow-through bursting head      


Technological and construction solutions used while manufacturing the presented equipment are the property of MEMPEX and are protected by the patent law.



Stage III - Installation of a new well, removal of shoring, restoration of the surface.


     The installation of concrete circles is carried out inside the shoring and within the shoring system. This means that the shoring is being lifted as subsequent circles comprising the well are lowered and mounted. The shoring is lifted dy a lifting bar and two lifting cylinders. The lifting bar rests on the concrete circles. The empty spaces that appear in the annular space between the new well and the shoring are filled-up with soil. Once this space is filled, the shoring is lifted by one step and a new concrete circle is added.

     Why heavy equipment is not used when dismounting the shoring?

     The shoring is lifted on its own by means of two hydraulic cylinders and a lifting bar resting on support points inside the shoring. That is why there is no need to bring heavy equipment such as piledrivers (including impact and vibrational pile drivers) or even excavators, which are used to extract traditional shoring systems (sometimes by pulling them up violently). This brings a number of benefits:

   - economical: reducing the cost of bringing heavy equipment;
   - safety: smooth and safe lifting of the shoring;
   - environment: minimum interference with road and pedestrian traffic and green areas.


The entire well replacement can be carried out even in one day.

Selected case studies:

Baranovichi, January 2018., commissioning of the new 2,0 m shoring system. The shoring will be used to install new wells on the main sewer collector to be rehabilitated with CIPP liner.

Sterlitamak (Russia), August 2017. Commissioning of OR-1.5 modular shoring system with MNB-50 machine. A total of 160 meters of pipe was replaced using the method of static pipe bursting within 2 days during the field training and commissioning.

Minsk, 2016. Pipe bursting with MNB-50 in modular shoring. Depth: 5.5 m, lenght of the section: 36 m. One well was replaced in the process.

Minsk, 2015. Directional pipe pushing under the Minsk Ring Road. MNB-50 machine inside the OR-1.5 shoring system is used.

Minsk, 2015. Another shot under the Minsk Ring Road. In total at least 1,5 km of new PE pipes was installed using this method.

Minsk, 2014. Emergency pipe repair in the city.


We invite you to comment and ask questions by e-mail at a.kazanski@mempex.com.