# data[].attributes.body
While reading upon top-down construction, I was fascinated by its systematic process in achieving this process. In top-down construction, the lower and upper structures can be carried out simultaneously helping to reduce construction times as well as cost. I had also learnt that this method ables the construction of a basement in congested areas such as CBD conditions however, the disadvantages of dust and noise problems and the restricted access for material handling and accessibility to the construction site needs to be considered when working in the CBD area.

# data[].attributes.body
Upon reading and discovering top-down construction I was surprised at this innovative technique that was so efficient (time/money). This method did not require the extra money for equipment and time taken to excavate the entire basement but parts. I also learned there were disadvantages. It should be noted there is not one solution that fits all projects and due diligence should be taken in selecting the best method.

# data[].attributes.body
With initial reading and viewing of the notes and learning about the top-down construction method, this did help to give a basic understanding of its principles.

Upon review of the case study one thing I have learned for sure is that this method of construction allows the basement and above structure to be simultaneously constructed. I would be really interested in seeing a Revit/CAD model video etc. on how this method of construction starts from scratch on a high-rise CBD structure.
Most importantly another area that would be beneficial for our learning is the safety aspect and the controls & permits in place before commencement.

# data[].attributes.body
The use of the top-down construction in this project proved effective for the southern half of the project whilst the northern half used conventional construction methods. This allowed for the southern half of the project to reduce overall cost and shorten the construction duration. With the benefits achieved in this project, top-down approach is difficult to implement and requires extensive analysis prior to selection as advantages or disadvantages may be outweighed by the other resulting in unexpected expenditures.

# data[].attributes.body
I was shocked when I first saw this construction method. I am impressed by this method because of  using this method can saving money and time. For example, I don't need to excavate the whole basement but parts of them. For construction filed, Quality, Time, Money are important. By using this method we can achieve the construction requirement.

# data[].attributes.body
Prior to the article I was unaware of the top-down construction method, and found it rather fascinating that a building could have the lower and upper structures of the building being constructed simultaneously. Despite the advantages of the silent press rulers that reduce excessive noise pollution. The complexity of this method would mean a great need for detailed planning and regulations for the process to ensure that the 'cons' or challenges of this method doesn't negatively effect the project.

# data[].attributes.body
The article emphasised the versatility of top-down construction, which facilitated the use of steel sheet piles as temporary shoring. I was surprised to learn that the sheet piling was also used as a permanent basement wall, because it acted as a barrier to water and methane seepage; methane being an issue that I didn’t know impacted basement construction.

Furthermore, using a silent press piler was an alternative to vibrating that I hadn’t heard of before. This unique process not only circumvented excessive noise pollution, but also helped shorten the construction schedule by two months, by moving below-grade construction off the critical path.

# data[].attributes.body
The top-down method of construction was interesting to me because i had never heard of it before. Although it may lead to dust and noise issues, it means that the excavation of lower levels can proceed at their own pace. It is a longer process compared to open cut method but is more appropriate for CBD conditions.

# data[].attributes.body
I found this method of construction quite ingenious, it is not something i have heard of before. Obviously it is a more complex method of construction but the schedule benefits can be significant as shown in the case study. The added challenges of building up as well as constructing the basements simultaneously would require a very experienced team i would imagine.

# data[].attributes.body
It is interesting to see how the basement construction principles are applied in this project. It can be inferred that the site condition is quite different between the southern and northern part as top-down and conventional method is adopted respectively. The southern half basement is probably larger and with more complex environment. Though the top-down construction has the potential to reduce construction time, the process is rather challenging and would require higher level of management to coordinate well with every aspect.

# data[].attributes.body
Top-Down is a new construction method enable workers start constructing above ground before the underground part. While it improves the work efficiency as there is a great saving on construction time. In the other hand, shorter operation time reduce the cost on facilities and labor. It is not necessary for construction companies excavate all soil. In addition, time-saving ensures there is no heavy burden for traffic.

# data[].attributes.body
It's quite an interesting project given that it adopted the top-down method of construction in basement which means that the top part of the building was built simultaneously. It used the silent press piler which is an extraordinary equipment that enabled pile driving to occur with minimum effects to its surroundings. For top-down method in this project to be successful, I can only imagine the amount of pressure and efficiency required of the construction manager to keep on top of all the details with strict attention. It also required intensive preparation and preliminary findings to compile the necessary details as accurately as possible to avoid repercussions of associated risks and delay. Management of this project was well documented and executed thoroughly throughout the process. Although the project saved costs in adopting the top-down method, the effective collaboration on all stakeholders was also a major contribution as without the proper coordination of these, associated risks in this method could have also resulted in loss. Thus, I find it equally important that all aspects of this project was thoroughly investigated and implemented with the construction method and the technology forming part of its success.

# data[].attributes.body
Prior to this case study, I only knew of the information presented in the online lecture. However after reading this case study, I was amazed to see the intricacy of an actual example of this, where all factors had to be considered and the construction method needing to adapt to, such as the sheet piling and the material chosen and the equipment used. I can only imagine the amount of pressure this placed on the managers, where considerations such as the machinery size needing to be spot on, otherwise it will not fit in the lower level construction. Even more impressive was how well this detailed work was successful, showing that the planning of this was flawless

# data[].attributes.body
Was unaware of the ability to construct the building superstructure simultaneously with the excavation and construction of basement levels. This reduces the total scheduled completion time of the project, making it an efficient method of construction. It also surprised me that steel sheet piles can be used as a permanent basement wall. It has a relatively easy and quick installation, where a 'silent' press piler was used to press the sheet piles into place

# data[].attributes.body
Prior to reading this article I was unaware that the one building can be split up and constructed in two different methods. One being a top down construction and the other half being constructed conventionally. This would allow for lessons to be learnt and advantages and disadvantages being analysed for each method. I was unaware that this method of construction (top down) even existed so it is very fascinating indeed. Do many building adopt this approach nowadays??

# data[].attributes.body
As I knew from online lecture, the most attractive point of top-down construction is shorter construction time, since the lower and higher parts can work simultaneously. And above-grade levels prior to the construction of below-grade levels within the same footprint to mitigate temporary shoring issues in below. The article shows that different techniques adopted according to different site condition, such as up-down methodology was chosen for the southern half of the project site. Since the coordination is much more complex for this technique, the working flow should be managed properly by experienced contractor.

# data[].attributes.body
Top-down technique is a fast yet economically efficient method of basement construction. In addition to cutting down on the costs & time to install struts, rock anchors & formwork, it may also reduce costs & duration for prelims & overheads associated with project construction. Depending on the experience of the contractor, the same site team may take care of the simultaneous construction of both the substructure & superstructure; hence, further reduce the cost of the  project team  & associated overhead costs (estimators, accounts, etc.). Quality of the building may also be superior as many of the main structural elements are prefabricated; whereas structural elements used in open cut, & cut & cover methods, are often cast insitu.

# data[].attributes.body
Prior to reading this article, I was aware of the top down method, however did not realise that it could be used in combination with conventional methods on the same building.  On this Los Angeles high rise development, the top down method of construction was used on the southern half of the development, while conventional methods were used on the northern half.

# data[].attributes.body
What i learnt and found most interesting was that there are machinery that can minimise noise and vibratory impact on neighbouring buildings and the surrounding urban suburbs. The one in the article is described as a "silent" press piler and was used to hydraulically press the sheets of pile into place. This silent press piler was laser guided, it utilised previously placed sections as reaction piles and was self advancing. With a "silent" press piler, its said that the noise was equal to a semi truck and vibrations were non-existent, which is very impressive on a  large scale. This machinery, most likely more costly to hire than the normal piler, would increase sustainability elements and keep councils and neighbouring buildings happy; which is a large advantage.

# data[].attributes.body
The article discussed the up down design and construction methodology for high rise developments, one of the interesting factors is the amount of time saved by using this methodology. Using up down construction resulted in increased quality and needs no footing or piles to support the sheet piles. This methodology has number of advantages that can be used in various commercial and residential projects.

# data[].attributes.body
It was very interesting to learn from the article that steel sheet piles can be used as permanent basement walls, the speed and ease of installation from sheet piles has facilitated the use of up-down construction. From the article it is evident that the use of permanent steel sheet piles provided a cheaper yet structurally sound alternative to concrete basement walls. What was particularly interesting is the silent press piler used to install the sheet piles, the machine minimises the noise and vibrations of ‘traditional’ loud hammering on surrounding buildings. With this new method “vibrations were virtually non-existent”, this technique can prove highly effective for construction surrounded by numerous other buildings. The article proves that new technologies, construction methods and stakeholder collaboration improves the efficiency and cost-savings of construction.

# data[].attributes.body
I have never heard of the Top Down method and the complexity of it amazed me. Has it been used in Australia, sydney at all??? The coordination of the whole process would have to be very logistically challenging. With already so much trucks coming and going to the site, on top of all them you have excavators and the spoil coming and going it would be a sight to see in real life especially the underground excavation post slab being poured.

# data[].attributes.headline
Advantages of Top-Down method Name: Sasha Rouhani

# data[].attributes.subject
Advantages of Top-Down method Name: Sasha Rouhani

# data[].attributes.body
1-      This system brought Financial advantages for investors. Application of top-down method result in saving two months in construction schedule, two months saving means two months less fixed costs plus two months more rent collection. This method also removed Below-grade construction from critical path which is an advantage for planning and scheduling.

2-      This method enabled construction of basement in congested areas and because it is used in conjunction with conventional method, the builder has taken advantage of both methods when required to get the best result.

3-      The sheet piles that originally used for excavation stayed in place after construction as basement which is another saving in time and resources.

# data[].attributes.body
z5160479
I found this article interesting as they used pressed piles, which were driven into the ground to ensure the wall would not collapse under excavation. I find top down construction interesting in the fact that they fit the excavator and material through a small gap in the slab

# data[].attributes.body
Name :  Chi Tak Cheng
From the article, I learnt that pressed-in piles method enables piles to be driven into the ground using the extraction resistance of the previously driven piles.  It is quite impressive that a small machine can generate such a strong force. This method has a high energy efficiency.

# data[].attributes.body
Name: Riza Yosia Sunindijo
This top-down construction used steel sheet piles as its retaining wall. It is unusual to use this displacement method because of its potential to cause vibration during their installation, particularly in a constrained space like the CBD area. The use of laser guided press piler reduced this risk to an acceptable level. This shows the importance of innovation and collaboration among stakeholders to come up with practical solutions. This website explains this press piling method further: https://www.giken.com/en/press-in_method/press-in-principle/