The soil is composed by particles (minerals and sometimes organic material) and voids (pores) between these particles. These voids usually contain air or water. The general principle of grouting is to fill or reducing the voids with a different material (usually a cementitious grout or a chemical grout) therefore improving the mechanical properties of the soil and reducing its permeability.
Cohesive soils like clays have limited voids and are less prone to grouting techniques. Granular soils like sands and gravels have large volumes of voids and are more compatible with grouting techniques.
These techniques may be summarized in:
- Permeation grouting;
- Compaction grouting;
- Intrusion grouting;
- Jet grouting;
- Rock grouting.
Please note that each of these categories have several different methods of installation.
Consist in filling the soil pores with grout without disturbing the soil formation. The grout permeates through the soil particles filling the voids occupied by the air or water, ideally without moving the soil particles. The installation is conducted by low pressure injection of low viscosity grout. The grout viscosity is selected based on the permeability of the soil.
This technique is used for:
- Control ground water flow, especially during excavation;
- Increasing the stand-up time of soils when excavated;
- Increase the strength of soils
- Control settlements
This technique is versatile and therefore often used when site access or presence of utility encroachments are a challenge. On the other hand, the grout can travel though the soil only for relatively limited distances, depending on the soil permeability.
We define retaining walls as bottom to top structures, meaning they are built starting from the foundation and adding fill with some type of fascia till reaching the desired elevation.
Examples of retaining walls are cantilever walls, gravity walls and Mechanically Stabilized Earth (MSE) walls.
We refer to support of excavation (SOE) or earth retention, as top to bottom solutions, where the soil adjacent to an excavation is supported by some means of reinforcement. Examples are excavations alongside highways, shafts, pits, trenches, basements, underground garages, channels banks and others. Some of the solutions are soil nail walls with shotcrete, tie back walls, pile and lagging walls, secant piles wall, slurry walls, diaphragm walls, soil grouting, sheet pile walls.
Each solution is engineered for the specific application. The selection is often based on several factors:
- Geotechnical conditions
- Loads
- Drainage
- Cut and fill
- Geometry
- Aesthetics
- Costs
- Access / footprint
Depending on the geometry, flow and geotechnical conditions there may be several options. Professional design is recommended. Options may be erosion control blankets, anchored turf reinforced mattress or revetments to stop erosion from further advancements. For land reclamation you may want to consider reinforced soil slopes or retaining structures. When possible, revegetation and proper drainage are usually very effective for controlling erosion.
Rockfall (or rock fall) is an engineering science belonging to rock mechanic principles. As first step we identify what is the application, whether it is an existing rock rim, a slope or a rock cut, rock excavation. Then we do a rock mass characterization, identifying the rock mass properties, localizing which blocks are considered unstable, the detachment zone of these blocks and the type of initial movement those blocks may have. Once detached the blocks gain energy proportionally to their mass and velocity during the fall, but they also lose energy due to impacts along the trajectory, air friction and type of motion (for instance a rolling motion along a slope will dissipate more energy compared to a free vertical fall from a rock rim). We analyze all the above with kinematics and dynamics principles and statistical approach.
Once we are comfortable with our analyses and we determine the block trajectory, we consider one of the following solutions or the combination of several of them:
- Rockfall trenching;
- Rockfall embankments;
- Rockfall barriers;
- Debris flow barriers;
- Rockfall attenuators;
- Simple draperies;
- Pinned draperies;
- Rock bolting;
- Rock scaling.
Under the rockfall protection term, we define active solutions those options that prevent the event from occurring while passive solutions are the ones which are intended to control rockfall impacts. Understanding that rockfall analyses are based on kinematic energy, the impact energy is usually dissipated by controlled deformation of the structure intercepting the rock trajectory. The selection between one solution and the other is based typically on expected energy to be dissipated, access and footprint available. Other factors may also be considered.
It depends. What you’d want to know is:
- What type of range are you envisioning (i.e. standard earthen berms)?
- What type of soil do you have on your land? Are these soils suitable for proper compaction?
- Based on the size of the range you want, are you willing to have a pit dug out?
When we build a range, we can offer solutions that reduce the width backstop and sidewalls. Preparing properly the foundations and using reinforced soil techniques, prefabricated cages or pile walls systems, we can reach the backstop height optimizing the surface area. This increases the space available to accommodate the actual training ground.