Marco Concrete Lifting

Basement Waterproofing Methods

gwenn — Fri, 13 Jan 2012 10:45:01 +0000

Basement waterproofing refers to methods and techniques used to prevent water from seeping or entering the basement of a house or any other structures. Over the years, several basement waterproofing techniques have been developed to address the issue of leaky basements. Some of the most effective methods are done below ground such as sealers and drainage systems. Waterproofing also helps prevent other major problems such as mold infestations and decay from occurring.

Tanking is a waterproofing method that involves coating the outside of the basement with a chemical substance that forms a membrane to keep the water out. The membrane acts as a seal that prevents water from seeping into the basement walls. This method is usually done during the initial construction of basements.

Another waterproofing method is the Cavity Drainage System. This involves the installation of a sump pump and a thin plastic honeycomb membrane on the basement walls and floors. The basement floors are constructed in such a way that it is angled or sloped towards the sump pump so that any water that enters the basement will flow into the pump and be taken outside. There are some drawbacks to this method like the system being useless if the electricity suddenly goes out and the honeycomb membrane being vulnerable to mold and mildew. This method though is ideal for structures that are built on areas that only experience light rains throughout the year.

On the other hand, those that are built on areas that experience heavy downpours would want to apply the exterior foundation drain method. A drainage system that consists of a series of pipes is installed within the structure and ends up on the exterior foundation wall. The pipes divert the water away from the basement and out into the open.

The last basement waterproofing method is referred to as the sani-tred system. This method is done by applying three different types of chemicals on the walls inside the basement. Permaflex is a chemical used to prime the basement’s walls and floors and is the first chemical to be applied. The second chemical is a two-part compound that is applied to the wall cracks and joints as well as to the wall-to-floor junction. Lastly, the walls get another coating of Permaflex. Once it dries up, the basement is sealed, ready to be used as well as maintenance free.

Waterproofing is considered as an essential preventive measure for keeping a structure dry and comfortable. It can help sustain stability and save on long term maintenance costs since a bit of cleaning is all you need once a good, solid waterproofing method is applied. Simple tasks such as keeping the rain gutters clean can already make a huge difference in avoiding a leaky basement since leaves and debris can be one cause of water clogging.

A Quick Guide On Micropiles

gwenn — Wed, 04 Jan 2012 01:52:46 +0000

Back in the early 1950s, there was a huge demand for new and innovative techniques that would provide a solution for underpinning historical buildings and structures that has suffered damage with time. Thus, micropiles were born. Since then, micropiles have been widely used as one of the elements for foundation designs to resist static and seismic loading conditions.

Micropiles are rotary drilled and grout reinforced small-diameter piles, usually less than 300mm, which can be installed to depths of up to 200 feet and can penetrate through very dense layers of rock and soil. Micropiles are classified according to their design application and grouting method. The design application refers to the function of the micropile while the grouting method refers to the grout capacity. The design application is further subdivided into two types. One is where the micropile is directly loaded either laterally or axially and the pile reinforcement resists the majority of the load. This design is used to transfer loads to deeper and more competent or stable layers. The second design is where the micropile is used to reinforce the soil to make a reinforced soil composite that will resist the applied load. On the other hand, the grouting method is based mainly on the method of placement and pressure under which the grouting is used during construction.

When installing a micropile, it is important to determine which drilling method to use that will cause the least disturbance to the overall surrounding environment such as the soil and nearby structures, while still achieving the required drilling performance. The actual process of installing micropiles starts with determining the geological condition of the site so that the engineer can consider which design and micropile type to use. Then, the site is marked as to where the micropiles will be positioned. This is followed by the actual drilling into the bedrock using specialized drilling rigs and equipments. Once the drilling is complete, the drilled hole is flushed out to remove any remaining debris after which the drilling rods are removed and replaced with reinforcement steel rods.
Water is then pumped into the grouting hose attached to the steel rods for some final cleaning and to make sure that the hole is not blocked during the lowering process. Grout is then pumped into the drilled hole and the process is completed once the grout reaches ground level.

Though micropiles are more commonly used for underpinning or the strengthening of an existing foundation, it can also be used in tasks such as modifying existing structures to make it more resistant to earthquakes, replacing deteriorating foundation systems and it can be used as an added support for structures during renovations. It is also the preferred method to use for environmentally sensitive projects as it creates very minimal disturbance to the surrounding area.

Pressure Grouting 101

gwenn — Wed, 04 Jan 2012 01:52:24 +0000

Pressure grouting is a term often used to describe the process of using pressure to directly inject grout in an isolated or empty space such as fracture or cavities in rocks, soils or artificial structures to fix common foundation problems like vibrations, leakage, water cut-off and deficient bearing. The grout may be of cement in nature, resinous, or based on a solution chemical mixture. It can be injected as deep as 80 feet or more underground. It is a very versatile approach to ground improvement.

The injection methods as well as the materials to be used are customized specifically to a project. These options provide a wide range of choices for a project’s grouting program. The main challenge is to find the best collaboration of method and materials to achieve the desired objectives and results. It is also important to hire a contractor with the knowledge and expertise in the grouting process to make sure that the grouting program and the project itself is implemented efficiently and effectively.

The process of grouting is simple. First, holes are drilled into the slabs or foundation to allow the insertion of injection pipes through the voids and the soil. The grout hose is then connected to the pipe to load and inject the grout mixture. As the mixture is being pumped through the pipes, it permeates the soil and fills in the gaps to stabilize the slab. As the pressure starts to rise, the pipe is lifted as it builds up the soil. The process is complete when the grout mixture fills the void all the way to the bottom of slab, which makes it completely stabilized.

Though pressure grouting is sometimes used to treat unstable foundations of buildings, it is more generally used in smaller foundation projects. In fact, pressure grouting is the most cost-effective solution to cracks and leakages in domestic houses. It is non-hazardous, no waste spoil disposal, non-destructive and adaptable to existing foundations and it emits low noise and vibrations.

Pressure grouting is an essential procedure in any type of construction. It main purpose is to solidify and strengthen the foundation soils to ensure that the structure will remain stable even in the long run. Other purposes of grouting include the strengthening or reducing of water flow through a formation, correct faults in concrete structures, lift structures that have settled and in cases of dams, to reduce the amount of water leakage through the rock. The bottom line is pressure grouting does not only increase the load bearing capacity of the structure but it will also prevent infiltration and leakage such as soil further seeping into cavities that can again weaken the foundation.

The Basics of Foundation Repairs

gwenn — Fri, 30 Dec 2011 03:21:22 +0000

The foundation is the most important structural part of any infrastructure, whether it is an office building, a hotel or even your own home. Therefore, any signs of wear and tear should be addressed immediately to prevent further damage and higher expense costs. There are a lot of foundation repair specialists and contractors that are readily available to attend to such problems. Some can even be found online for easier access to their service, product and contact details and some even offer free estimates and analysis.

Most foundation problems revolve around an imbalanced foundation settlement making the entire structure unstable and unsafe. Some factors that can cause imbalance to the foundation include the soil condition, the land area where the structure was constructed and the maintenance of the structure itself. Most people ignore the first signs of any foundation problems such as cracked and bulging walls. This is the biggest mistake they can make when it comes to foundation repair since by ignoring the situation, the problem only gets worse over time. Thus, when it comes to foundation problems, it is better to take action sooner rather than later to avoid further inconvenience and expense.

An important thing to consider when it comes to foundation repair is to understand the problem. Since the foundation is the main support system of an infrastructure, it’s supposed to be constructed in such a way that the structure lies upon a smooth, flat and even surface. If this is not the case, chances are that the soil in which the foundation was built on starts to change and move. This can be due to undetected air pockets that create voids or empty spaces within the soil, which weakens it and its load bearing capacity.

As the soil moves, the foundation along with the entire structure moves with it. This leads to problems with the structural areas within the infrastructure. Cracks in the walls can suddenly appear and the floors start to become uneven. There are instances wherein doors are difficult to open or close due to misalignment. A noticeable separation between the walls and the floor or ceiling is evident. These are just some of the common signs of foundation problems that should be acted upon as quickly as possible to avoid further foundation failure, which in turn can lead to the entire infrastructure collapsing.

Again, foundation problems shouldn’t be ignored and some people address these problems by doing the fixing themselves. Although there are a lot of foundation repair do-it-yourself kits and guides out in the market, it is still advisable to seek help from a professional who has gathered years of experience and has built a good reputation. Foundation repair experts know which structural areas to survey and problem signs to look out for. They use that data as their basis for analysis and coming up with the ideal solution to fix the problem. Doing a temporary fix yourself might seem to be a quick and convenient solution for the moment but in the long run, it will be something that you would have to fix over and over again. Foundation repair experts locate and fix the main cause of foundation issues so that you can be assured that there will be no further issues in the near future.

Tieback Anchors: A Cost-effective Stabilization Solution

gwenn — Fri, 30 Dec 2011 00:59:04 +0000

Each year, landslides cause millions of dollars in damages to the transportation and utility sectors and all other forms of infrastructure. It is considered as one of the most devastating natural hazards that can wipe out anything in its path. One such devastating landslide wiped entire towns and villages in Columbia back in 1985 where it claimed the lives of 20,000 people. This is the reason why engineers and contractors continue to research and develop designs and approaches that can help stabilize landslides and prevent it from dealing immense damage to any area. One such approach was the use of tieback anchors since it can be used to penetrate the failure surface and apply a resisting force directly to the sliding mass to prevent or limit any further movement.

Tieback anchors, also referred to as ground anchors, are horizontal anchors used to reinforce retaining walls for stability. One end of the tieback is anchored to a wall while the other end is anchored to a solid structure that is attached firmly into the ground with sufficient resistance. This allows the structure to resists forces such as landslides that would otherwise cause it to lean. It can be installed with minimal excavation and then simply covered again with backfill to provide a more “natural” and artistic solution to complicated landslide problems.

Tieback anchors were traditionally known to be used for temporary excavation applications that gradually moved to being permanent construction applications. However, with the advancement of technology, a wider range of experience and a broader knowledge on advance corrosion protection techniques, tieback anchors are now being considered as an option or alternative to cost-effective and economical solutions for landslide stabilization. Tieback anchors cost less when compared to other options for landslide preventive measures such as building of concrete and stem walls, excavations and relocations just to name a few. It is estimated that tieback systems costs roughly one third less than the construction of stem walls since the cost increases as the height of the stem wall rises while tieback walls seem to be independent of the height factor.

Installing a tieback anchor is critical to its performance. Choosing the correct drilling technique should be carefully considered and based upon the following factors: the availability of equipment, the soil type and the noise or vibrations constraints. The actual installation process follows these basic construction procedures. First is to drill the hole followed by the insertion of the tendon into the hole while making sure that it is properly aligned. Next is to fill the hole with the grout mixture. Once the tieback anchor is installed, testing is performed to make sure that the installation was successful in meeting the required objectives.

Overall, tieback anchors prove to be a rapid and effective ground and structural stabilization method that utilizes a simple drilling system and requires minimal manpower resources. Its benefits include minimal disturbance to the surrounding area during installation, is suitable to all ground conditions and offers a wide-range of options for design flexibility.