Jet grout uygulaması sonrası yapılan kalite kontrol testleri ve değerlendirilmesi
Quality test methods and evaluation regarding jet grouting
Yazar: ARZU DOĞRU YILMAZ
Danışman: PROF. DR. HÜSEYİN YILDIRIM
İstanbul Teknik Üniversitesi / Fen Bilimleri Enstitüsü / İnşaat Mühendisliği Ana Bilim Dalı / Zemin Mekaniği ve Geoteknik Mühendisliği Bilim Dalı
Derece: Yüksek Lisans, 2016
Konu: İnşaat Mühendisliği = Civil Engineering
Dizin: Kazık yükleme deneyi = Pile load test ; Kohezyonlu zemin = Cohesive soil ; Zemin güçlendirme = Soil reinforcement ; Şişen zeminler = Swelling soils

Özet:
Zayıf zemin üzerine gelecek yüzeysel temellerin taşıma gücü yetersizliği, büyük oturmalar, vb… gibi nedenler ile zeminin yetersiz kaldığı durumlarda çözüm olarak derin temeller ve/veya zemin iyileştirme yöntemleri kullanılması düşünülür.
Son 70 yıldır teknolojinin de gelişimiyle farklı makine ve ekipman tasarımlarıyla istenilen derinliklerde ve amaçta çeşitli derin temel sistemi uygulanmaları yapılmaktadır. Özellikle derin temel sistemleri içerisinde sıkça kullanılan kazık temeller, pek çok mühendislik yapısının elverişsiz zeminde yapılmasına olanak sağlamaktadır.
Kazıklı temellerin kullanılamaması durumunda zeminin ıslah edilmesi tercih edilebilir. Jet grout tekniği ile ıslah yönteminin amacı; yüksek basınçla zemine çimento şerbeti enjekte ederken, belli hızla yukarı çekilen enjeksiyon borusunun aynı zamanda belli hızla döndürülmesi ile bir çimento – zemin karışımı (soilcrete) oluşturmaktır. Bu işlem sonucunda herhangi bir donatı kullanılmadan daha dayanımlı ve yeni bir zemin kütlesi oluşturulmaktadır.
Tez çalışması sırasında zemin ıslah yöntemlerinden biri olan biri olan jet grout yönteminin işletim parametreleri, imalat aşamaları, yöntemin avantajları ve dezavantajları, uygulama sonrası yapılan kalite kontrol testleri, testlerin sonuçlarının değerlendirilmesi ve irdelenmesi üzerinde durulmuştur.
Tezin uygulama kısmında, imalatı 2015 yılında tamamlanan Hampton by Hilton Bolu Otel ve Konferans Salonu Projesi jet grout imalatları üzerinde durulmuş olup; uygulaması yapılan jet grout kolonlarının kalite kontrol testleri sonuçları irdelenmiştir. Proje kapsamında kalite kontrol testleri olarak; karot numune üzerinde basınç dayanımı, bütünlük testi ve yükleme testi yapılmıştır.
Bu tez kapsamında zemin ıslah yöntemlerinden biri olan jet grout yönteminin çalışma prensibi irdelenmiş; bu sistem sonrası yapılan kalite kontrol testleri açıklanmıştır. Sistemin uygulanabilirliğinin ve performansının anlaşılması için Hampton by Hilton Bolu Otel ve Konferans Salonu projesi incelenmiştir. Bu kapsamda yapılan mühendislik uygulamalarının teorik hesapları desteklediğinin gösterilmesi amaç edinilmiştir.

Abstract:
When the ground is insufficient such as bearing capacity problems of shallow foundations on weak soils, large setting etc.., deep foundations and/or soil improvement methods are considered for solving the problems.
Many constructions of deep foundation can be made desired depth and purpose with different machine and equipment last 70 years. Especially pile foundations commonly used the purpose of the main function is to transfer the load to lower levels in the ground which are capable of sustaining the load with an adequate factor of safety.
Soil improvement methods can be preferred to when pile foundations can not be used. The purpose of the jet grouting, uses a high-pressure jet of fluid to break up and loosen the soil at depth in a borehole and to mix it with a self-hardening grout to form columns in the ground. At the end of this proses more strength and new soilcrete is occured without reinforcement.
Jet grouting systems define that a special drill bit with horizontal and vertical high speed water jets to cut soils and constructed hard impervious columns by pumping grout through the nozzles. Jet grouting systems is not depend on grain size distrubitions. There are three fluid systems and can make coulums in any soils. The advantages of jet grouting systems can be listed below:

•	It is more economical and efficient than the other injection methods.
•	Jet grout columns can be made different geometry.
•	Jet grout columns can be made any depths which is desired.
•	Application of columns are easier than other methos of improvement methods.

Jet grouting is a construction process using a high kinetic energy jet of fluid to break up and loosen the ground, and mix it with a thin slurry. It is not truly grouting but rather a hydrodynamic mix-in-place technique producing a soil-cement material. Jet grouting makes use of three physical processes, singly or in combination:

•	the very high speed jet loosens the soil
•	the jetting fluid washes some of the soil to the surface
•	the slurry adds a binder to the soil mix

The methods most used to mitigate the problem of the ground-structure interaction consist of the employment of the before-seen isolation systems and of some ground brace techniques, which are adopted above all on the low-quality ones (categories D and E). The most diffused techniques are the jet-grouting technique and the pile work technique. The jet-grouting technique consists of injecting in the subsoil some liquid concrete by means of a drill. When this concrete hardens it forms a sort of column that consolidates the surrounding soil. This process is repeated on all areas of the structure. The pile work technique consists of using piles, which, once inserted in the ground, support the foundation and the building above, by moving the loads or the weights towards soil layers that are deeper and therefore more compact and movement-resistant.
During this thesis; operating parameters, construction phases and advantages and disadvantages, quality control tests after construction, examination of test procedures of jet grouting which is a soil improvement methods are explained.
Different kind of piles have been discussed. Before choosing of pile types, economical situations and factor of safety of design use. According to material used in their installation can be classified below:

•	Concrete piles
•	Steel Piles
•	Timber piles

During the design methods of pile foudation, pile loads can be divided in three groups. This loads are listed below:

•	Dynamic formulas
•	Static formulas
•	Load tests

Pile load test method is the most certain method to determine the bearing capacity of piles. Testing a pile for failure make sure that valuable information about pile setting and bearing capacity to design engineer.
The static pile load test is common method of testing to considered capacity of piles. It is applicaple to all kind of pile types and it involves the direct measurement of pile heads displacement. Pile load test have three objectives:

- To establish load-deflections relationships in the pile-soil systems
- To determine capacity of the pile-soil system 
- To determine load distrubition in the pile-soil system

Three types of loading for a static load tests are given below:

- The quick load test
- The incremental static load test
- The constant rate of penetration test

The static load test was conducted in general accordance with ASTM-D1143. 
During the this thesis; design criteria of stone coulums, construction phases and the reasons what designer uses soil improvement are explained. Additionaly, operating parameters of jet grouting which is a soil improvement methods, construction phases, advantages and limitations of the methods are explained.
In the application part of the thesis, Hampton by Hilton Bolu Hotel and Conference Hole Project on which was completed in 2015 was given for an case study and quality tests procedures and examination were given. Unconfned compression test, pile integrity test and load test were applied during this case study.
In this thesis, jet grouting which is a soil improvement method is investigated and told quality control test after application. For understanding of applicability and performance of the system, Hampton by Hilton Bolu Hotel and Conference Hole Project is investigated. The purpose of the thesis, teoritical and application results are support eachother.